I've had this model for years - it was a gift from my brother. At the time I was building a Nurgle-themed Warhammer 40k army (still have most of the Nurgle bits of that force and as a bonus the Great Unclean will work great with them too). I'm glad I finally got around to getting him painted.
I wanted him a bit darker than the Plaguebearers so I shifted the palette a shade darker for each stage. Rather than coating the thing in gore, I stuck to the bright green innards to tie the model in with the rest of the Daemons. This monster makes a great centerpiece for a Nurgle Daemon army and another heavy hitter if I want to combine the Daemons with my Rotbringers.