what is the color umber burned and what is it for?
Burnt umber is a brownish pigment that warms up the skintone. It has an orangey tone to it so I always mix with a bit of blue to neutralize
also serves to darken the kit?
Light washes (burnt umber mixed with lots of thinner) don’t darken the kit unless you are doing lots of layers. I, generally use 1-2 washes at the very end to liven up the skin tone. I have made AA babies by using lots of layers of burnt umber mixed with blue though so it is a useful color to have.