Hi Rand. In this case I looked for a creepy fleshy tone of colors, finding my way on instinct. To make colors look realistic it is good to make subtle shifts between many colors within one single color. So, while this worm has a single color covering all of its body, there a in fact many different colors within that main color - like orange, blue, brown, ocher, purple, red, grey etc. (I can see you're doing that on your images as well.) I also play around with my colors a lot, using Photoshop Tools like 'Image>Adjustments>Variations', and 'Image>Adjustments>Hue/Saturation...'





Apart from that I suppose it is a matter of studying nature, and experience. Values also matter a lot for the color experience. Many people use too much light, and darkness, ending up with almost no mid-values. Mid-values are richer in color and bring a better feeling of substance/matter/surface.





Say hello to the Myrdraal from me.

Cheers!