Start priming with white. I used Scale 75 primer with airbrush. You want to avoid black for this one because black will kill the luminosity of a color like blue and in the end it will feel dull and grey.
I started with the base colors. I used Olive Green from Vallejo mixed with Black Green. I wetblended it and kept the lighter color in the “face” area.
I kept adding lighter colors to the face. I added Sunny Skintone to the eyes and face area.
Did a wash over all the piece. Athonian Camoshade for the lower areas and a warmer color like Serpahim Sepia for the head.
At this stage I randomly stippled green and ochre colors to bring some kind of stony texture and make some organic noise. I just used a sponge like those from the blisters dipped in paint and then wiped off a little bit to remove excess paint and add colors where it feels right. Then add colors where it felt right.
I painted the eyes in Mephiston Red and sprayed with the airbrush a very thin coat of contrast Blood Angels Red around those eyes to simulate a glowing/fleshy effect.
At this point I defined the eyes more by highlighting the eyelids with red and blacklining with ink the inside of the eyes and deep recesses.
I then painted the inner part of the tentacle with Violet Red from Vallejo.
Keep layering lighter reds to the eyes if you want roundiness, but take into account most will be lost after the gloss varnish.
I highlighted the tentacles, adding German Orange to the mix and used a high quality varnish with gloss finish to cover the eyes and the inner part of the tentacles. I used Marabu but any good varnish will work.