Hello Simon,
It is not possible to provide a definitive answer to this question. Yes, you are correct in thinking that late war boats were in general darker than early boats. There were very few light grey boats by the end of the war. Most were either quite dark or dark grey.
The lower hull was RAL7016, as we know.
I have looked again at the painting regulations for 1944 and they state (for upper hull and tower) that 58 was to be used. There were three types of 58 paint but it doesn't state which version of 58. There were three versions (58 Schlickgrau; 58/1 Blaugrau; 58/2 Blauschwarz). It isn't possible to tell from a b&w photo whether a boat had Schlickgrau or Blaugrau. Blauschwarz is very dark indeed but probably was used on some boats (U 1052 for example).
Although the regulations state 58, there may have been cases (with paint stocks being low and supply issues) where Dunkelgrau 52 could have been used on some boats. Certainly some boats were as dark as Dunkelgrau 52.
If you are debating what colour to choose for your drawing it might be best to play it safe and go for one of the 58 colours as that is what is in the regulations. What boat are you drawing and at what time?
You probably already realise this but the present paint colour of U 995 is not representative of a typical late war boat.
Cheers,
Dougie
