This is the process I use for painting blue eyes, something that I did not cover in depth in my other eye painting guide! I'll be using my NaMoPaiMo horse as my model who was in need of some peepers.
I find a reference as always. Certain colors and patterns produce different types of blue eyes. This model is a minimal sabino and despite not having any markings on his body, will be given some blue eyes.
I start by painting his third eyelid. I use a darker pink/red for the outer edge and a light pink for the inner area against the eye. I don't have to worry about the edges of my colors at this stage as I'll go in and shape the third eyelid with his eyewhites.
Next I add the outer edge of his iris. My reference had a light grey color around it. I'll add a little Paynes Gray to this color for a cooler grey, but I'm careful not to let it get too blue. It would blend in too much with his actual iris color if I did. It also makes the transition between his iris and third eyelid softer, instead of a darker color, but this varies from horse to horse.
Now I'll start painting his iris. Unlike darker eyes, I work from dark to light, starting with a mix of Paynes Gray and Prussian Blue. I add this to the middle of the iris right where his pupil will be. I paint this in an irregular shape. I'll tint this mix slightly and paint a lighter blue color around the darker area. Finally, I'll shape these colors with an even stronger tint in the outermost areas of the eyes. I'll make this application uneven to keep the edges of the darker blue colors irregular. I'm careful to leave a small line of the grey color on the outer edge of the iris.
The last thing I'll add is his eyelashes and then his eyes are finished!
