Clothing colour

While cultures differ in their specific distinctions, clothing and its colour is a major part of life amongst the darkness. Historically, clothing has always been a part of visibility between people.
Some cultures employ the use of face markings using pigment to help visibility. Others rely more on light reflective fabric sewn into outfits.
Bright yellow, orange, blue face markings help visibility on skin. Special pigments and fabrics that reflect light. Shopkeepers, bards, performers, guards. Only a little bit in each outfit. Too much is over the top and flashy, narcissistic and self absorbed. Theatre versions of those outfits will employ more reflective fabrics than usually accepted.
Bare faces and all fabric that doesn't reflect - reclusive, loners. spies and mercenaries. typically still has a bright colour - a lack of such usually means the individual is actively trying not to be noticed. blending in with a crowd will usually employ regular dress, actively avoiding being seen will avoid bright colour altogether. 

Black/dark colours - Implied to be purposefully hiding in the shadows. untrustworthy, sneaky. Dark reds, blacks, and blues are the cores of this idea, while dark versions of other colours tend to evoke less of a reaction. Very bright colours - visibility, draw attention to self. It is typically considered unusual to not have some bright colour on you, unless you are up to no good.