I printed this model from Thingiverse # 4839997 (scaled down) on my Monoprice Mini Delta 3D printer. It took a lot of time to remove all the support material due to the small scale (and I broke the head off in the process). So I used some superglue to re-attach the head, and spackled the broken gaps in the neck before I primed it using spray auto primer.
I painted the belly of the snake light green and the scales a darker green. If you pay attention, you can see that I used a lighter version of each color in the “lit” areas and a darker version for the “shadow” areas. I also used a solid pink in the entire mouth and tongue at this stage.
Then I dry-brushed yellow over the scales (and also washed some yellow over the larger “belly” under-scales that show on the neck.
I washed the body with a violet tint which darkens the areas between the scales (using more tint near the bottom where the upper scales meet the belly scales), and also washed red inside the mouth. (Because it was a 3D print, a bit of red seeped out to the side of the mouth as shown below, but I touched that up with some green on top of it. You might also notice that I’m using solid black to highlight the shadow over the eye and the nostrils.
For the final detail work, I used a turquoise blue for the eye, with a vertical black line, and picked out the teeth with white.