The greys tended to be a blur, depending upon age and fading due too exposure to the elements, as a kid I went on a couple of the ships including HMS Hermes and HMS Yarmouth and the colours varied even across the individual ships. (My father did a secondment on HMS Yarmouth from AMTE)
RIMMER is directing the scutters in painting the walls.
RIMMER: (To the scutters) That's the way. Smooth and even. Up and down.
LISTER walks out of his quarters.
RIMMER: Ah, Lister. Bonnen Maitenon. Didn't wake you, I trust?
LISTER: No, I haven't been to bed yet.
RIMMER: But it's five past five in the morning. It's practically
lunchtime.
LISTER: (Noticing the scutters are doing) What are you doing?
RIMMER: It's called "work," Lister. I didn't think you'd recognize it.
W-O-R-K. It is in the dictionary. (To the scutters) Come on, paint!
Paint, paint, paint!
LISTER: But why are they painting the color the same color it was before?
RIMMER: They're changing it from Ocean Gray to Military Gray. Something
that should've been done a long time ago.
LISTER: Looks exactly the same to me.
RIMMER: No. No, no, no. (Points to a section of a wall.) That's the new
Military Gray bit there, and that's the dowdy, old, nasty Ocean Gray
bit there.
The two bits look identical.
RIMMER: Or is it the other way 'round?