Like June, if I want to color my ganache, I add the gel color to the cream before pouring it over the chocolate. It is really hard to gauge how much color is required, so use sparingly. If you want a specific color, it would probably be easier to dry brush it with petal dust, once the drip has completely set.
Another option is to use candy melts in the desired color. I’ve used candy melts and several different types of white chocolate (chips and bars) for ganache and I don’t find a great deal of difference in taste, when doing a drip. It is such a thin layer of chocolate, it does not add significant flavor, so the type of chocolate matters little. That is my opinion, of course. Some bakers are probably horrified that I even suggested candy melts.
Sugar Sugar by SSmiley
