Hello,
The following page is quite helpful -
http://www.ipmsstockholm.org/colorcharts/stuff_eng_colorcharts_fs.htmAssuming the FS codes are correct on that page, then I would recommend the following -
Most common upper colour Dunkelgrau 51, FS35237, Polly Scale PCA817
Alternative upper colour Hellgrau 50, FS36440, Polly Scale PCA825
Lower hull colour Schiffsbodenfarbe III Grau I, FS36081, Polly Scale P:500014
For the wooden deck you could just take a black and a dark brown and match whatever you want depending on the length of time since it was stained. If you want one just out of dry-dock black or almost black would work. If you look at page 42 in the Wolf Pack downloadable file there are details about the wooden deck.
Cheers,
Dougie