Publishers of technology books, eBooks, and videos for creative people

Home > Articles > Design > Adobe Photoshop

When Too Much Is Just Right: A Decade of Changes in LAB Color Technique

In 2005, Dan Margulis revolutionized workflows with a best-selling survey of the uses of the LAB colorspace. Ten years later, a new edition of Photoshop LAB Color is out. In this article, Dan uses automation and common sense to improve on the most popular moves of the first edition.
Like this article? We recommend

A decade ago, Photoshop LAB Color: The Canyon Conundrum and Other Adventures in the Most Powerful Colorspace burst onto the scene. Its signature move was to enhance color—and color variation—with steep curves applied to the A and B channels. This approach worked wonders with images featuring naturally dull colors, such as the canyons referred to the book's title. Let's look at an example of this basic technique, as taught in the first edition, and then discuss how we can do better a decade later.

Simple, Fast, Effective Color Adjustment: How an Excellent Technique Was Improved and Automated

The original canyon image shown in Figure 1 is transformed into the version in Figure 2 by applying the curves in Figure 3, in LAB mode. The red tickmarks in the contrast-only L channel show the range of most of the canyon; detail is enhanced by steepening this part of the curve. The color-only A and B curves are also steepened, but they pass through their original center points, which is where they define neutrality. Therefore, color becomes more intense, but grays don't change. If you think the image still lacks color, make the A and B curves even steeper; if the color is too intense, flatten the curves slightly, always holding the center point constant.

Figure 1 An original photo of a canyon in a Canadian national park.

Figure 2 A corrected version using techniques shown in the first edition.

Figure 3 The LAB curves that produced Figure 2.

This color adjustment was simple, fast, and very effective for its time—but I no longer work that way. The reasons are part technological, part more experience, and part more common sense.

How vertical to make the A and B curves depends on the image. The better-known canyon in Figure 4 starts out much duller than the one in Figure 1. Yet very steep curves can transform it into the result in Figure 5. I think it's already too colorful—yet LAB would permit making it even more vivid, if desired. And why not? If done on an adjustment layer, it's easy enough to reduce opacity to taste—or to find a more agreeable way to cut back the color.

Figure 4 The grandest and most iconic canyon in the world.

Figure 5 The workflow advocated in the new edition always shoots for excessive color at first, followed by an intelligent decision on how to back off. Here, although the entire image is too colorful, the blue background is more objectionable than the red rocks.

I don't accept either Figure 4 or Figure 5, but Figure 5 tells me more about what's possible with this image than Figure 4 does. To me, the blue background is more objectionable than the red foreground. Therefore, in toning down the overall color, I would choose a method that discriminates against those blues—or possibly against all dark colors. LAB has more options for doing this than you'll find in any other colorspace.

My policy today is always to go for color overkill and then back off, rather than starting with a duller image and trying to force the right amount of color into it. As this statement implies, I no longer make custom curves. The original canyon of Figure 1 needs less color added than Figure 4 does, but why worry? They can both use the same set of curves, and then we can figure out how far to back off the color in each image.

If the same set of curves will be applied to each image, automation is the way to go. A simple action will do the trick.

Something similar to the small move between the canyons of Figure 1 and Figure 2 can be done without LAB, but something as strong as between Figure 4 and Figure 5 probably can't be. Everything you're about to see definitely can't be.

Driving Colors Apart

Now, another take on the Grand Canyon image. Based on a technique shown in the first edition of Photoshop LAB Color, this approach drives colors apart, as opposed to intensifying them generally. Back then, I needed complicated curving. This time, it's an action. Getting from Figure 6 (complete with selection) to Figure 7 is just a single click. The selection is used only to suggest to Photoshop what the important ranges of the image look like. It's not actually used to correct the file.

Figure 6 A new take on the Grand Canyon image starts with an "advisory" selection that gives Photoshop an idea of which colors are most important.

Figure 7 The new MMM action uses the advisory selection to add variation—not simply more color—to the original image.

You've probably never seen an action with this kind of "advisory" selection before. And the complexity of developing a strategy from it suggests a very long action of close to 100 individual steps. Such a monster would have been out of the question 10 years ago because it would have taken too long to run. And anyway, I didn't know enough to write it. Today, it runs quickly, and is part of a suite of such actions you can download for free.

Its advantages are evident here: The reddish rocks are emphasized, but, unlike in Figure 5, the blue background is not. We can tone down the result in many ways, or unite it with a similarly toned-down version of Figure 5. In fact, a second free action lets you combine three different approaches, in whatever proportion or intensity you like. Let's have a look, using a new image, to see how LAB opens creative possibilities that are available nowhere else.

Figure 8, the original photo, shows the rough selection that will guide the process. Or, rather, the two selections. Any Photoshop method of selecting works with this action, including multiple selections—even Select All. The result can be divided into three parts.

The version in Figure 9 is contrast-only, or in LAB terms, exclusively in the L channel. It seeks to enhance detail in areas similar to those of the selection. It's not easy to see in this image, but you should be able to detect that the lighter greens in the background of Figure 9 break away from the darker trees better than they do in Figure 8. Similarly, there's more texture in the animal's coat.

Figure 8 Any selection method, including multiple selections or even Select All, can guide the action.

Figure 9 These images break down the individual elements of the MMM action when applied to Figure 8. Here, the action adds contrast without changing color.

Figure 10 is the equivalent of the earlier Figure 7. It's not more colorful as such; instead, the colors are driven apart from one another. Figure 11 is the one that intensifies color. The major difference: The Figure 10 approach considers it acceptable to modify hue. Note that the background foliage is bluer in Figure 10 than in Figure 11.

Figure 10 This is the color-variation contribution.

Figure 11 This version adds color only.

All three of these versions merge together, reinforcing each other, to create Figure 12. Too much? Certainly, but what do you expect from a maneuver that takes no account of the nature of the image? The question now is how to back off. LAB offers infinite options. We could simply reduce the opacity of the entire effect. Or we could reduce, increase, or eliminate any of its three components—even selectively, and with much more flexibility than is available in other colorspaces.

Figure 12 Figure 9-Figure 11 combine to make this overly colored version, which reveals that the oranges are more offensive than the greens. LAB makes it easy to reduce one more than the other.

It's too easy to look at Figure 12 and say "way too colorful." Instead, look at the individual components. The background is too intense, but not by much, and many people would accept it as is. Nothing is wrong with the dark parts of the bison, but the lighter areas of the coat and parts of the tree trunks are definitely too orange. We should look for a way to tone down these parts more than the others. Here again, LAB has a decisive advantage.

Masking and Blend If

We often need to isolate objects from their backgrounds or from each other, using masks or similar techniques. It's always helpful if a certain channel has at least the beginnings of such a mask, so we don't have to create it manually. The A and B channels of LAB, which are color-only, are much more likely to qualify than any RGB or CMYK channel, all of which portray darkness as well as color. Many more objects can be defined uniquely by their color than by their darkness. That factor makes the Blend If sliders, found in the Layer Style menu of the Layers palette, far more useful in LAB than elsewhere. We could use it fruitfully in the bison image, but for clarity I'll use the flower image in Figure 13.

Figure 13 It's much easier to distinguish objects by their color than by their darkness.

To show how LAB can isolate these flowers, for the sake of argument we'll say that the picture should be transformed so that the flowers retain their color but everything else becomes black-and-white, as shown in Figure 14.

Figure 14 To illustrate how easily LAB can isolate the flowers, everything else has been desaturated.

The first part of the exercise is easy enough, whether in LAB or, say, RGB. Duplicate the base layer, and then use Image: Adjustments>Desaturate. Now the top layer is a full black-and-white. The problem is to restore the flowers, which requires some kind of layer mask or Blend If to disable the parts of the top layer that contain flowers.

In RGB, this is easier said than done. In many places, the flowers are light in the red channel while dark in the other two; this is what makes them overall red or pink. Unfortunately, the trellis in the background, which is not red but also not exactly white, is just as light as the flowers, and many reflections off the green leaves are just as dark as the darkest areas of the flowers in the red channel. So the red channel can be the start of a mask, but will need work to finalize it.

In LAB, there's no problem at all. The A channel runs from magenta to green. By excluding the top layer wherever the underlying layer is significantly magenta (see Figure 15), we can detach all the variously colored flowers from the background.

Figure 15 The Blend If command is much more powerful in LAB than in other colorspaces. To create Figure 14, a duplicate layer was desaturated, and then Blend If excluded parts of it with a magenta component.

We use a similar procedure in the B channel, which is yellow versus blue. The sky, for example, is frequently the only blue object in an image—easily isolated with Blend If.

You might think that the B channel would be able to exclude the objectionable orange parts of the bison and trees back in Figure 12, but it's not that easy. True, these areas are much more yellow than they are blue, but so is the background vegetation, so Blend If can't distinguish the two. The areas are also more yellow than they are magenta; or, in LAB terms, they're more B-positive than A-positive. However, they are A-positive, and the background, being more green than it is magenta, is B-negative. Therefore, Blend If can be used in the A channel to isolate the orange areas. They can be restored to their original dull color, or to anything in between the colors in Figure 12 and Figure 8. And this is in addition to all the options suggested by Figure 9, Figure 10 , and Figure 11.

This unique ability to find definitions of objects in the A and B channels is much greater than was the case a decade ago, when Photoshop LAB Color was published. That's why I devote so much of the Second Edition to channel structure.

I hope we've established that LAB offers creative flexibility that can't be found elsewhere. It also can create wildly excessive colors. Why would you want to do that? Well, the bison image is a good example. Figure 8 is the original. It surely needs more intensity. But can you tell by looking at Figure 8 that the bison's coat and the tree trunks will be the limiting factors as to how much intensity you can add?

The title of this article is derived from the title of Chapter 4 in the new edition: "Too Much Is Just Right." Take that principle to heart: It's easier to work with too much color than not enough—especially if you know your LAB.

Peachpit Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Peachpit and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Peachpit products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive:

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020