[Chris Saper]

Hi Margaret,

I don't know about the crimson, but I use Grumbacher's Thalo Yellow Green, and it is an incredibly useful color, even though it looks like a mistake (a bad one) when you first squeeze it out. It desaturates the reds and oranges in skin ( or anywhere) without changing the value - it is much lighter than Viridian or Thalo Green.

I think one of the other manufacturers makes a similar color called Cinnabar.