Andrew Devis has series of newer tutorials on color in After Effects and Premiere. Here are the ones for AE that use the Color Finesse plug-in, which ships free with After Effects...
- Primary Color Correction in After Effects
- Secondary Color Correction in After Effects
- The Vectorscope in After Effects
- Waveform Monitors in After Effects
The Synthetic Aperture training resources page lists almost every other resource available for Color Finesse. Related articles include: White balance + more with Color Finesse and Profiles and color management in AE at AE Portal, How to talk to a Colorist by Alexis Van Hurkman, and a review of the book Color Correction For Video by Steve Hullfish at AEtuts.
By the way, there are 2 other 3rd party plug-ins that provide easier monitoring in AE (not in a modal dialog box): Synthetic Aperture Test Gear and Metadma ScopoGigio. An interesting free Pixel Bender filter was posted on Video Copilot last year, Waveform Monitor by Peter Werner, shown below.