Todd Kopriva posted on the Color correction effects and blending modes new in After Effects CS5. Todd lists a few references for CS5 additions of three new CC effects from Photoshop -- Black & White, Vibrance, and Selective Color -- and two new blending modes -- Divide and Subtract.
If you've followed up on earlier posts on Lynda.com tutorials, you're set. If not Lynda.com offers free 24-hour pass to their Online Training Library that would easily cover the 4 hours of tutorials by Mark Christiansen and by Chris Meyer. Of course, the Lynda brand has plenty of membership options for reviewing all 12 new CS5 courses now in the Online Training Library.