Originally Posted by SquirrellyCakes
The Wilton whitener product, here is a caution, if you read the label, you are only supposed to use a few drops of this. It is a bleach and probably not a good idea to use a whole lot of it as some folks do.
Actually, Squirrelly (and thank you again for the help you gave me months ago on the Wilton site!), the White-White icing color is *not* a bleach. I've got my bottle right here and it contains "Titanium Dioxide, Glycerin and Water". Titanium Dioxide is what makes Desitin and zinc sunblock sticks white, and is a major component in acrylic paints and cosmetics. It's a pigment, not a dye, and therefore refracts light much better (dyes tend to diffuse/absorb light), and because of that, makes the dyed icing look whiter/brighter.
Wikipedia: "TiO2 is also an effective opacifier in powder form, where it is employed as a pigment to provide whiteness and opacity to products such as paints, coatings, plastics, papers, inks, foods, and most toothpastes. In cosmetic and skin care products, titanium dioxide is used both as a pigment and a thickener, and in almost every sunblock with a physical blocker, titanium dioxide is found both because of its refractive index and its resistance to discoloration under ultraviolet light. This advantage enhances its stability and ability to protect the skin from ultraviolet light."
I'm thinking, as an aside, because of the stability vs UV discoloration, a royal icing with some of the White-White in it and then dyed with the fading blues/purples, that the fading may not be as bad as it could be without that same kind of TiO2 in it. Fascinating concept.