Hi Christian,
It's obviously hard to say for sure, but I personally don't think B5 was on Prince of Wales. If it was, then it was in a very, very bad state by the time it went to Singapore.
I also am doubtful that B6 was on Prince of Wales.
I have a feeling that it may have been MS1, HFG, possibly MS3 but I'm not convinced, 507C, MS4A and white. I can't prove that.
So long as everyone understands this isn't finished and there is still more to confirm the exact nature of B6, and that I am NOT offering to have PM discussions with 15 different users about it (we'll publish the findings when we're ready

) we know that B6 was not a light green. We've already published our little piece on B5 and whilst I had a few emails about it generally, I've had no actual challenge on it including from John Snyder to whom I sent a copy, as well as Jeff Herne who co-authored the RN charts on Steel Navy. So, it seems everyone has accepted that B5 was indeed a strong blue - I'm not seeing that anywhere on Prince of Wales in the brief colour cine film. I'm not seeing B6 as it is shown here either. A quick note at this point is that this B6 is much bluer than the National Archives sample which seems to have turned rather greyish, but agrees on tone. The National Archives sample has no green about it whatsoever - I matched it as a low saturated reddish blue. This that you see here does have a basis however and corroborates well with 2 sources. I won't share those yet. This colour may yet change a little, but it definitely will not be green!
The following borrowed from EJ Foeth to save navigating backwards.
