I actually prefer to paint red over black, which most people do not like to do (I think most like to paint it over white). I use a mix of Vallejo Cadmium Maroon (recommended to me by Finn Kisch) and Reaper Aged Red Brick (recommended to me by Anne Foerster) as a base. To this I add red gore for a few highlite layers, then blood red. Depending on how dark a red I want, I might go up to pure blood red and then add a little fiery orange to that for final highlites.