custom slider help

[Rynow]

I am very new to SKD tools and programming...

I have figured out how to create a slider the changes the opacity of a view object but now can't figure how to do the following:

Slider that goes from one color at the left and as the slider gets closer to the middle the whiter the image becomes then from the middle (white) it becomes more of another color.

IE

purple ......... white.........yellow



any help or links would be super.
Thx