From http://www.w3schools.com (Copyright Refsnes Data)
With Tint Tweening you can change the color of an object.
In this example you will learn how to change the color of an object.
Step 1
Choose Insert > New Symbol.
Note: To add Tint effects the object must be a symbol.
Step 2
Name the symbol "changecolor" and select the Graphic option in
Behavior. Click OK.
Note: You will now be taken to the symbol generator in the Flash program. Here you create symbols. Symbols can be dragged to the stage of your movie after you have created them.
Step 3
Choose the Text tool in the left toolbox. Choose Text > Size > 36 from
the top menu to make the text big. Choose Text > Style > Bold to make the
text thick.
Step 4
Click in the work area and write "Color Changing Text".
Step 5
Jump back to the movie. Do this by choosing Edit > Edit
Movie.
Step 6
Insert the symbol you just created into the movie. Choose Window >
Library. Select the "changecolor" symbol and drag it into the middle
of the Stage.
Step 7
Insert a keyframe in Frame 15 and in Frame 30.
Step 8
Go to Frame 15. Right click on the text in the Stage. In the pop-up menu,
choose Panels > Effect.
Step 9
Choose Tint from the drop down menu. A color map will show. Set the colors
to: R=0, G=255, B=0.
Step 10
Click on the Timeline any place between Frame 1 and Frame 15. Then right
click and choose Create Motion Tween.
Step 11
Click on the Timeline any place between Frame 15 and Frame 30. Then right
click and choose Create Motion Tween.
Step 12
Choose Control > Test Movie from the top menu to test your Flash movie.
From http://www.w3schools.com (Copyright Refsnes Data)