Gimp:How do you color eyes like this?

personally since I am brand new to Gimp i would go to deviant art and find a free to use stock photo. I would c+p that to a new image. Cut out the eye with a path tool. stretch the edges of the path to make it a circle and encomp the eye. copy the selected section and paste it to a new transparent layer. Save it as a xcf(er something like that) so that it can be further tweaked when you paste it to a new layer. if you have some mad drawing skills I would look on youtube for drawing realistic eyes Gimp tutorial.