Trying to match up some different video shots in AE. Final Cut has a speedy tool in their 3-Way Color Corrector. It's called Match Hue.
You eyedrop a color in your correctly exposed shot. It then loads up an eyedropper in the lift, gamma, or gain wheel. Use that new eyedropper to select the same color in your bad shot and it automatically shifts all three wheels to match the your good shot. It's not perfect, but it usually gets a shot 90% there with a couple clicks.
Color Finesse (which was automatically installed into After Effects CS3/CS4) has its Match Color function.
It works differently than FCP's (or Photoshop's, or...) so don't get frustrated right away. You can also select the color model for matching (RGB, HSL, etc.). Try each to see what works best for your specific task.
Match Color adjusts CF's regular color correction controls, so you can manually fine-tune the results after the initial button press.
Color matching is a difficult problem, not because figuring out how to turn one color into another is all that difficult, but because of the effect on all the other things in the scene which are equally affected by the color change.