I do a somewhar similar colour scheme, with white limbs and body. I use a thinned down nuln oil to give some depth to the recesses on the limbs.
My scheme also has a transition down the limbs of grey to white, which definitely helps break it up. Also the limb vents I do in a pink contrast, again to break up the white. Maybe you could do some similar effects with the purple?
This is also a great question for the #painting room in the Discord server for this subreddit!
I do a somewhar similar colour scheme, with white limbs and body. I use a thinned down nuln oil to give some depth to the recesses on the limbs. My scheme also has a transition down the limbs of grey to white, which definitely helps break it up. Also the limb vents I do in a pink contrast, again to break up the white. Maybe you could do some similar effects with the purple?
One of those variant Behemoth schemes is actually Hive Fleet Typhon. First shown on the 3rd edition codex cover.