Greatcoat basically a medium grey with a Vallejo brown violet wash and highlights with khaki or hemp.
Trousers are a very dark green eg matt army green or Russian green* also for the top of the cap. Bands of the cap can be red or blue for (jagers).The Jagers had black cross belts.
Mickael Werth's Sebastopol contribution has the Navy colours which would again be a very dark green similar to the trousers of the infantry.
*refers to WWII Russian aircraft
Federal Standard Colours
Grey FS36492,FS36293 (brown violet 887 see Vallejo charts)
Greens FS34092 FS34083
Hemp FS30475 or FS33245
overcoats/greatcoats could be FS36165 without shading. I can't see a Humbrol match.
The Jager blue would be FS35095 or FS35180
Dark green for most. A few officers wore black as a kind of provincial style and this was common for high ranking officers in the Crimea. If you look at the first pic of Mickael's (Sebastopol) you will see he has the mix of uniform colours also the box art on set 051. The Navy often wore the same greatcoat as the army when fighting as infantry but had black cross belts. The double breasted pea jacket was a grey beige see box art set 027.