Yeah, but I think there are two things going on- 1) the tendency of vintage photography to bleach colour meaning what you see isn't actually what the model looks like 2) my avoidance of using white as a highlight colour and black as a shade hence not desaturating the coloursRegarding muted colours, have you tried following John Blanche's painting instructions from Heroes for Wargames and painting instructions from Rogue Trader rulebook?