Might I recommend some Vallejo colours which match the various colours ?
First , the raw , unblancoed webbing : use 914 or 880. The colour varied slightly depending on where it was manufactured .
Blanco seems to have come in three main colours :~
Khaki Green light ( use 881 )
Khaki Green Medium ( use 888 +978 about 1:1 )
And Khaki Green 3, which was a dark olive green colour ( use 889+888 ).
And obviously there would be worn and faded versions of all those, depending on how long the man had been in the field.
Blanco was used on the personal webbing , such as braces, haversack pouches, holsters etc. The colour used was a matter of Regimantal preference.
But probably not used on things like utility pouches, Bren spares wallets etc, since they were essentially add-on, throwaway items
rather than part of a man's personal kit.
This pic shows the real thing , original webbing straps, blancoed in those three main colours.
This pic tends to look a little too blue-green ,which seems to be a trick of Photoshop .
In reality the colours should be a little more yellow-brown , just a touch.