46" RAF Crash Tender
Not withstanding the preceding chat about 'scale or not scale' and to answer your original question.
As Dodgy and some others say planked and varnished looks very nice, on a sports boat, yacht or fantasy designs, but totally inappropriate for a naval, RAF Marine Branch or working boat. It would be far too labour and cost intensive to maintain. Not to mention downright dangerous on a wet deck.
Attached therefore is a copy (100th generation?🤔) of the original Vosper painting plan for the #93 and 94 Fireboats / Crash Tenders as built.
In this it is clear (but not so easy to read so I made a negative of the original) that the decks and superstructure (coamings and cabin tops) were all the same colour grey. Deck non-slip, superstructure smooth.
IMHO this is the colour-
https://www.e-paint.co.uk/Lab_values.asp?cRange=BS%20381C&cRef=BS381C%20631&cDescription=Light%20grey
As shown in this chart of the BS381 colours of the time.
https://www.e-paint.co.uk/BS381%20Colourchart.asp
Or you could use
https://www.e-paint.co.uk/Colour_alternatives.asp
It might also be a BS651 colour, in which case-
https://www.e-paint.co.uk/Colour_alternatives.asp?cRange=Pantone%20C&cRef=651%20C&metallic2=False&cDescription=
At the end of the proverbial day it's your choice. Just wanted to try to answer your actual question. Cheers, Doug😎
PS If scale accuracy, at least for the paint scheme is no longer important I'll quit my research and archive digging except for my own projects.