Modert tech to learn about ancient dyes.

There's a new technique on the block that can be used to detect and identify dyes, for example in leather: a variation of Raman spectroscopy coupled with laser blasts.

Here's the link to the Chemical and Engineering News article about it, and if you feel so inclined, you can also read the original paper in analytical chemistry. Lasers! Pricey spectrometers! Madder dye! What is not to like? (Well, it's not a loss-free method, so there's always that - but colour detection can rarely, if ever, be done without sacrificing a little bit of the material.)