chocolate just does that
sorry, should have included that it is buttercream icing just colored brown.
it wasn't mixed well enough.
also added salt and different exposure to light as it's used can effect color
ok, makes sense. thanks! just have to remember to mix it a little more then.
here's a thought for you--mix the color into a small amount of icing--a nice dollop off the spatula- i mix color with the metal spatula onto the clean counter top (or you might want to use a tray or the back of a tray) so that you can smear it out as thin as possible over and over and you can see that all is well combined--then mix that into the big batch--
mixing in a bowl--even a mixer sometimes will leave streaks and pops in icing color