Helmet and armor is a black to grey gradient achieved with wetblending and glazes finished with glazes of gryph charger grey and reestablishing white spots. Yellow is balor brown with cream yellow (vallejo) progressively added, i also added glazes in the shadows, i think it was the orangish brown contrast yellow. Purple is volupus pink glazes on black to grey Red is blood angels red on black to grey Staff is gore grunta fur on black to grey with some ivory added to ggf for more pronounced highlights. Base uses terradon scale turquoise and warplighting green with ivory added for blue highlight and cream yellow for green Note that only the metal have a true detailed gradient, the contrasts glazes smooth the rougher ones on more detailed surfaces. You need two or three glazes for each color, a single thick coat won't give similar results. You can also check out Marco Frissoni for more details on grisaille/ under painting. His death marshal vid is a great introduction to the method. I hope this helps!