I finally figured out the color scheme that I am going to use on my Kraken. This Reaper was a guinea pig, and underwent several different color schemes before I settled on this one.
The two main body colors subtly compliment each other while still providing a neutral base for the effects to pop.
The silver metal is primed with Army Painter Platemail, and layered up with Ironbreaker and Runefang Silver, before being washed with Drakenhoff Nightshade.
The armor plates are base coated with Dryad Bark, and layered up with Steel Legion Drab, Baneblade Brown, and edge highlights of Karak Stone.
The gold trim is base coated with Balthasar gold, and layered with Ghenna's gold. That is washed with Coelia Green Shade.
The glow effect is Moot Green layered with White Scar and then glazed green. On the next helljack I paint, I am going to add a layer of yellow between the green and white.
After the rust and corrosion effects, I drybrush the gold parts with golden griffon and the silver metal with necron compound.
The result is a bit lighter than the studio scheme, but not so bright as to not look evil.