Can you use powder to color fondant and decrease fade potential in purple. I had some fade really bad in 24 hrs the other day. Scared out flowers I am making for my first wedding cake. I plan to luster dust and have been running an "experiement" to see how it fades. Have left the light on in my working are for 2 days, we have energy saving bulbs in there, it is starting to fade some. Don't have time to buy no fade purple and cake store doesn't carry it. But wondered about coloring with powder purple instead of gel. Can you even color fondant with powder colors?
Purple has high fade rate - keep it out of the sun and fluro lighting. You might also try using Satin Ice pre-colored purple fondant. The stayability of the color might be better (at least it is with their black).
i heard gelatin fondant has a harder time keeping certain colors, like purple. i didn't hear much of an explanation, though.
I do think that the Satin Ice pre-colored purple holds its color better, but it still goes somewhat "blue", depending on light exposure.
If you use a purple that is pure food color, it shouldn't fade. I don't know if the readily available powdered colors are "pure" food colors, but I do know that those available from Beth Parvu at sugarpaste.com are pure and don't fade.
I have found that if you dust colored gum paste or fondant, either with petal dust or luster dust, the color doesn't fade. I think the dust acts like sun screen...............
FYI: HEre's the history on why red (and purple) fades: