I'm running into some issues color matching both in the lab and out. Obviously this has been an issue that has plagued the public since the dawn of color cosmetics and I'd like to know - with help from the community - what are my tools as an amateur cosmetic chemist?
For example, if I'm crafting the perfect color match for someone's skin using a foundation (think: Prescriptives), and I have available to me the primary inputs (iron oxides) are there ways to objectively measure my accuracy? I'm thinking of tools like Sephora's spectrophotometer, which might let me know if I'm off in any direction.
I also understand that color match in practice is truly in the eye of the person being matched... but I don't have any formal training and I'm wondering what I missed out on with regard to matching color.. Any tips?