I don't recall much colour in Hartnell's outfit at all, other than the ring on his hand, and I think his tie (or one of them at least) may have been a very deep, dark blue. But everything else was pretty much in monochrome shades if I recall correctly.
Troughton on the other hand would prove more problematic, with his blue shirt and tie, his (red?) kerchief, red suspenders, and checkered pants, not to mention the brown fur coat if they included it. Just off the top of my head.
And therein lies the rub. If you can't easily do both in monochrome just with switch out alternate parts, then there's not much point in just doing one that way really, as it defeats the purpose a bit. So if they want to go down that path then I think they'd have to make the colour and monochrome versions separate variants.
And if they did do that, I have no idea which I'd buy. Part of me would want to honor how I saw them during their era, in black and white, but Pat also appeared in colour in the three multi-Doctor specials as well, while even old Bill did in the first, albeit briefly. Plus which, as a display, everything else would be in colour, so going with black and white versions would limit display options a bit.
Hopefully they'll just offer a colour version of Hartnell and I won't have to choose...
