Flamers of Tzeentch Skin
A recipe inspired by the Citadel app suggested colors with a few improvements to better mimic the original 'eavy Metal images.
- Spray with   Chaos Black , base head with   Naggaroth Night  and body with   Caledor Sky , fading with a 50:50 mix as an initial covering of transitions. 
 - Shade blue with   Drakenhof Nightshade  and purple parts with   Druchii Violet . No need for wet blending.
 - Layer blue skin with   Teclis Blue  and purple skin with   Xereus Purple , leaving out recesses in shade. 
 - Further layer/highlight blue skin with   Lothern Blue  and purple skin with   Genestealer Purple 
 - Final edge highlights can be done with gradually mixing   White  into   Lothern Blue  or   Genestealer Purple  
 
Flames
- Base with   Celestra Grey , wash with   Nihilakh Oxide  
 - Heavy drybrush with   Ulthuan Grey , then manually strengthen some of the ridges. Highlight sharpest edges and tips with   White