This is quite easy to do, but you'll need to familiarize yourself with how to control effects from within event sheets - please take a look at this thread which points to using the Set Color effect, and there are some good words in the manual to cover what you need to think about when using them.
As for varying the color, you'll need to change the Set Color parameters in events via the System. So... add the effect to your sprite and then you will be able to edit the effect parameters as required.