Can a fabric be engineered that doesn't get darker when wet?
One example is retroreflective fabric, which reflects light back where it came from and therefore shouldn't be affected by internal reflection of a water layer. But retroreflective fabric looks weird.
One idea is a dark material with lots of little pits, each with a white bottom. Any light reflected by the white bottom and not hitting the walls of the pit should be perpendicular enough to the surface that there won't be internal reflection. The overall albedo should be insensitive to wetness.
It could revolutionize clothing for people who sweat too much.
Probably the best approximation of this right now is the simplest: make the clothing of a low-reflective (black) material.
You can try a version of this at home: the discoloration of a black fabric is much less visible than that of a white fabric. An engineered low-reflective material should work better something merely dyed black, though.
One example is retroreflective fabric, which reflects light back where it came from and therefore shouldn't be affected by internal reflection of a water layer. But retroreflective fabric looks weird.
One idea is a dark material with lots of little pits, each with a white bottom. Any light reflected by the white bottom and not hitting the walls of the pit should be perpendicular enough to the surface that there won't be internal reflection. The overall albedo should be insensitive to wetness.
It could revolutionize clothing for people who sweat too much.