Can duochrome nail polish become monochrome over time?

Missionista must know…I have a couple of (Sephora) duochrome nail polishes. One shifts from lavender to grey, and the other from hot pink to orange. Lately, I’ve noticed less shift in the colors. The lavender one has lost almost all the grey, and the pink is much less orange. Can duochrome polishes become monochrome over time? Am I just hallucinating?

The Beauty Brains respond

Mon0-Chrome? Duo-Chrome? Personally, I prefer Safari. But enough with the bad browser puns.

How do DuoChrome polishes work?

As usual, the first thing we do when faced with a question like this is take a look at the ingredient list for clues about what might be happening. Strangely enough, when we looked at the ingredient list on Sephora’s website we noticed that they don’t list any colors for these nail polishes. (See below.) We even paid a visit to our local Sephora to find a bottle but we couldn’t find any of their duochrome polishes. Since we can’t tell which specific duo-colorants Sephora is using, we’ll have to take a small leap of faith here and assume that their technology is similar to that used in other duo color products.

For example one chemical supplier, Kobo Products Inc., sells a line of iridescent effect pigments that are based on Synthetic Fluorphlogopite (and) Silica (and) Titanium Dioxide). The particle sizes of these pigments range from 30 to 120 microns (which is our clue to what may be changing.) These pigments consist of multiple layers of tiny “sheets” that can reflect light differently depending on the angle from which they are viewed.

Is there any way to fix a DuoChrome polish gone bad?

These mineral-based pigments are quite inert, chemically speaking, so they really should not change over time. But since the color effect depends in part on particle size it is possible that as the product ages some agglomeration occurs where the pigment particles clump together. This could result in a shifting of the color.Depending on the extent of the clumping, simple shaking of the product may or may not be sufficient to reverse the process. (Sometimes particles have an electro-static attraction which is not easily broken.) As Missionista pointed out in our Forum her products are about 8 years old so it’s not surprising that some clumping could occur. The best solution may be a shopping trip to Sephora.

Duo Color Nail Polish Ingredients from

Butyl Acetate,Ethyl Acetate,Nitrocellulose, Phthalic Anhydride/Trimellitic Anhydride/Glycols Copolymer, CI 77499 (Iron Oxides), Acetyl Tributyl Citrate, Isopropyl Alcohol, Styrene/Acrylates Copolymer, Stearalkonium Hectorite, Acrylates Copolymer, Adipic Acid/Fumaric Acid/Phthalic Acid/Tricyclodecane Dimethanol Copolymer, Copernicia Cerifera (Carnauba) Wax, Polyvinyl Butyral, Citric Acid, Phosphoric Acid.