Reply #1: There are a couple ways [View All]

One is to paint the white chocolate with the color(s) of your choice.

Another way is to add food coloring to the white chocolate while it is melting.

You need to be careful about what type of food coloring you use, however. You can't use the water-based liquid stuff you find at the grocery store, because the water will cause the chocolate to "sieze" (turn clump together and turn lumpy and hard). Chocolate that has siezed can be "fixed" and re-melted with the addition of some cocoa butter, but it's really a pain to do.

You need either oil-based paste colors, which can be mixed into the melted chocolate, or powders (which you mix with melted cocoa butter).

There's a little info at the bottom of this page
http://www.baking911.com/chocolate/basics.htm

The easiest way, though, is to use colored coating discs - you can buy the colors that you want and just melt them, then use as melted or apply with a paint brush to your white chocolate, frosting or whatever you are making if you want to paint something. I've worked with these a little, and the are very easy to work with. You can combine with melted white chocolate for a light tint, or use for decorating.

Hope that helps a little. What are you making for your grandmother?