I like what you are doing with the juice packs and green ooze. I would dry brush or edge some more highlights on the purple and red, then hit it with ink or a wash to make it pop.
For the boltgun (maybe mithril silver) armour, I would use some nuln oil washes, the new nuln oil is so much better than the old inks on metalics, it's like a dream. 2-3 washes, and maybe some bright silver highlights before the last wash.
Great colours for sure. Such great minis those scourges.