Well done if you've already guessed what I'm about to discuss, those little tubes and pots of brightly coloured pink, ripe with the promise of revealing hidden secrets. Like the real oracles of ancient greece however I'm inclined to think of their predictions as deliberatley vague to provide the illusion of mystery.
All right all right I'll get to the point. This outbreak of colour change "shifts to the most perfect pink for YOU" products that simply refuses to go back to the mists of the 80's from which it crawled. I hate the way they use science, not complex science mind you, science we've all done in our fabulous free education, to attempt to baffle us into believing many ridiculous things, as I shall demonstrate below...
The products all claim to use "the pH in your skin" to adjust their colour. We will start by dissecting just this one claim. Let's assume that this is correct and the products do react to pH, by no means an impressive feat, red cabbage and Phenolphthalein can perform this circus trick and with their clear to pink spectrum it wouldn't surprise me if the chemical in these products was of similar origin or makeup.
Let's have a closer look then, pH is a measure of acid/alkaline. 7 in the middle is neutral. Stomach acid being the strongest acid at 1 and bleach the strongest alkali at 13. The general idea - that we got from school anyway - was that alkalis (at the levels most people would come into contact with) were far more dangerous than acids. Our skin is slightly acidic at pH 5.5. Looking at the way Phenolphthalein works i'd wager whatever chemical they use is very sensitive to slight variations around pH 5-6 with the pink darkening towards the more alkali end.
Indicators are a fairly basic, but visually impressive science and i'm not averse to their use as an exciting and entertaining product, I love science, I love pink, these are normally something i'd be all over. But no, what I don't like about these products is the way they heavily imply that whatever pink it turns is your OMGSUPERSECRETMOSTPERFECTESTJUSTFORYOUSPECIALSNOWFLAKE.
The product changes colour, it reacts to the pH in your skin, pH has nothing to do with tone or what suits you, the lipstick/gloss/blush CHANGES COLOUR - that is awesome in and of itself, I don't need to be told that it knows what suits me better than my own eyes do, I'm not going to buy it for fashion advice, If I buy it at all it's because it uses science and changes colour.