5. Show Your Colors
The Image Correction palette (under the Tools menu item) contains a variety of tools for improving and editing image colors. None of them is implemented at a level that will satisfy graphic designers or professional artists, but for casual tweaking and adjusting they’re pretty useful.
Included in the set are sliders for gamma, brightness, contrast, and saturation, but one that’s particularly fun to play with is the sepia slider, which quickly turns digital photos into nifty "Old Time" artwork for adding to newsletters and brochures.
Preview can’t undo these changes once implemented (beyond reverting to a previously saved copy of the file) so be sure to work on a copy, not the original.
Figure 5 Use the image correction tools to tweak the colors, but be sure and work on a copy, not the original.