Mussini Burnt Umber, Translucent/opaque.
It is dense, permenant and opaque/translucent.
Although this color is very important, I have noticed not only does it have a high
absorbsion rate of oil, it also attracts mold.
A suitable replacement can be made with Burnt Sienna and Ultramarine Blue.
That means Burnt Umber can be removed from a limited palette. Either color can be tinted to a neutral gray.
Find this color on a real color wheel.