Finishing off the Genestealer Cults kill team painting reports today is the Armoured Sentinel [previous parts are here and here]. This is the most expensive unit in the kill team in terms of sheer points value, but it is well worth it due to the plasma cannon that it is toting on its right hand side.
The painting scheme is a muted one using a codex grey style base coat over a black undercoat followed by a liberal wash of nuln oil. Sharp edges have been picked out in a cream colour (and then a second slightly lighter cream for the extreme edging) and metallic details added on the rear exhaust port and a few select other places.
The plasma on the sentinel is a green colour to provide a contrast to the more typically seen blues and reds. On the top, the lights have been done in reds and oranges. The final step was an application of some decals selected from various locations -- a skull (daily standard on many decal sheets) and some "script" from a 30k Mark 4 squad (Word Bearers style!). Combined with the base, the scheme is meant to communicate a stolen sentinel from the imperial guard stationed on whatever planet the cult has found a footing on.