I am red/green/brown colour blind, but not to the degree you describe.
I use celery green brits for the KMT as I don’t like the lack of available units from HBG in yellow green, but I do struggle to tell them apart from tan brits a little.
As a non-painter (except where I have to), all the major powers are relatively easy to get a full setup without painting (Apart from the gaps which are going to be addressed by base set 2 and other future sets, and the other important colours (red, yellow, plum, light grey, and Dutch orange) have got pretty good coverage, but I wish HBG would release their base sets in those colours to really fill in the gaps.
They could also do with a sub, mech inf and a carrier sculpt in the colours which don’t have those available (light grey, yellow, plum, Dutch orange, and white).
And then a load more yellow green sculpts so you can do KMT properly.
One day maybe…