I have a problem with painting, before two days I dyed (prime) basic grey, today I made certain shades with dark earth, next step:
1. Forget all and paint white, afterwards few shades, no wash.
2. Thin beam and white, wash and drybrush white.
3. Thin beam and 2 white - 2 Dark earth, afterwards 3 white - 1 Dark earth. . . . .
No clean white, wash and drybrush with white for lighting.
I look in 3rd solution because clean white appears to me little improbable in the conditions that acted, and as generally the white color pull as magnet the filth.

Sorry for bad English I use systran plus for translate GR -> English :-)