In regards of some Pertwee episodes being in B & W, it happened during the initial airings. Like the missing Hartnell and Troughton episodes, the Pertwee episodes were trashed after airing once in the UK and the US - the UK ones were obviously the original color films whereas the US were VHS color copies. The ones that survived where the black and white film versions. Anyway, when "Spearhead from Space"? aired in the US on a LA PBS station, a guy in the UK paid his friend in the US to rent a Betamax and purchase Betamax tapes to record the episode. His friend recorded the episode, but one of the episode, I think it was episode 4, was missing 20 seconds of footage since this was where his friend had to switch Betamax tapes as Betamax tapes, while superior to VHS tapes, had less record time. The guy then went to the US to visit the LA PBS station in hopes to get the colored tapes that was aired. He was told that after the serial aired, the tapes containing them were trashed. Sometime later, a guy in the UK wanted to test out a method of restoring color black and white film by overlaying the colors on top of negative. He not only did he use the original black and white film of the episode and the record betmax copies, but also another copy from another fan that had the missing 20 second segments. After the success of restoring the episode to color, other Pertwee episodes followed with similar techniques.
I read this on the Doctor Who Restoration website a few weeks ago. It is quite fascinating.
Anyway, I don't think black and white figures would sell well if the limit is huge, but if it is a few like 10-50, I think it would. Also, BC doesn't have to follow the same clothing pattern as their color versions especially how difficult it would be to get and match fabrics of different grey. I would think a simple plain black and white outfit with no eccentric designs (like the Unearthly child costume) would work. It doesn't necessarily have to be the same outfit as the color versions. Heck, they did it with the Underground Toys figures, why not these? Regardless, I certainly wouldn't buy them. however, it would be nice for the 3 first Doctors to come with a collector's edition of some sort. If not black and white figures, would exclusive accessories work like a different colored Troughton flute