Change+Eye+Color

#1 - select the iris before changing eye color
Select the iris of each eye with Gimp's lasso selection tool. Make the selection soft by using the **** dialog to avoid sharp edges, corners and stripes on the edge of your selection. I used a value of 7 px to make the selection in my image soft.

#2 - change eye color
Use the **** -dialog to change eye color with Gimp. This filter allows you to change eye color by changing the hue, saturation and value of all colors in a selection. Click on the hue that you would like to enhance. Adjust the saturation and value after you change the color to your desired hue. I used a roughness of 0,15 = 15% to change eye color in my image gradually.