My alpha channel for some reason is white instead of white and gray is there anyway I can change the solid color to multi color .
Alpha channels only show transparency. This is why they are only in black and white. White (100% shown), black (100% hidden) and gray (in-between see-through) are all that is needed to encode transparency. So, changing your alpha channel to be in color is a no-can-do. Perhaps you wanted to use layer masks instead to selectively show or hide colors on a layer?
If it's many-shades-of-gray-alpha layer shading on the other hand, you can just grab a black or gray brush and paint away on that alpha channel to get some quick transparency. Selections may also help you quickly edit this, too.