You cannot change your eye color with magick. It just doesn't work that way. You can, however, make them to appear changed by the color or your shirt. If you have blue eyes, especially light blue, you can wear a yellow shirt and it will appear you have green eyes. This mostly works with lighter color eyes. The only other way would be to get contacts. You cannot change your DNA.
I would suggest you to learn how magick works. And then learn to cast spells. It would be like handing a pencil to a small child and expecting him to write his name. If he doesn't know how, it's not going to happen. Not putting you down, just trying to make it easy to understand.
I am good with beginners, so feel free to mail me, as I don't want to make this a teaching lesson. Blessed Be...