I'll show you the process of this drawing. It's of two of my deer on The Endless Forest, Fae and Roe.
First, the sketch. It's a little hard to see, sorry. I typically sketch pretty light.
Next, line art. I do all my lines with a fine point sharpie pen.
On to color!! I start with the lightest colors first. It's easy to add dark over light, but very difficult to go the other way.
More details and color added. Fae, the butterfly colored doe, has around 9 different colors. Several browns, oranges, yellows, peach, white, grey and black. Roe has grey, black, 3 blues, white, beige, and 2 greens. Lots of colors! After I'm finished coloring, I go back and re-line everything.
This drawing took around 2 hours from start to finish. I use Prismacolor colored pencils. This is the technique I use on most of my artwork - traditional that is. My process is a bit different with digital.