You could use animations to force the desired effect.
Frame 0 - Uncoloured version
Frame 1 - Coloured Blue
Frame 2 - Coloured Red
Etc
Then create a colour pallet based on your choice. When the user clicks a new colour change a variable.
If the user then clicks the sprite and his variable is equal to red then change the sprites animation to red.
Or something along them lines.
Its a very long winded way of doing it but I'm sure this method would work or at the very least allow you to start making the game until someone else could point out a simpler way.
thank you for the solution,I think it must would work but it seems too complicated,lead to that I will spent too much time to make a lot of pictures....
Anyway thanks a lot guy <img src="smileys/smiley17.gif" border="0" align="middle" />