There's only that colour cine film (and all our family cine film from the 1960s, 1970s and early 80s looks heavily washed out despite only ever having been reeled a few times) and photos like this from the HMS Hood Association site:

... which could suggest a shade lighter than Home Fleet Grey.
We do know there were emergency mixes of 50/50 discussed in official documents, but these were
never given formal names or notation besides description as emergency mixes - i.e. certainly not 507B. I personally have seen nothing to suggest HMS Hood wouldn't have been Home Fleet Grey.
As part of a little research group with a few members of this forum, various potential 50/50 mixes have been made to try to arrive and something close to Colourcoats RN02 / what Raven, Snyder & Short notate as "AP507B" but whilst some get close to the reflectance factor, none get anywhere near the blue content.
Equally, the 507B and B5 chips on S&S which are extremely similar are nowhere near saturated enough to convince me/us that they are
fresh B5, but they may potentially be very faded B5.
My own Hood (still a WIP) is painted in RN02, and whilst I now believe this is incorrect (and yes, I know I need to repaint the main top mast white instead of grey), it does resemble the colour cinefilm to a degree although I know that cinefilm tends to be a spectacularly bad medium for capturing colours. I'm not changing this model now, but if I build a 1/200 Hood in future, I will use Home Fleet Grey.
