Hope it's not too light/ you guys can read it gTTHHHH also apologies if I used your oc in this! Please let me know if you want it removed.
Also you don't need to pay that much attention on the brush thumbnails I copypasted there- Just use whatever suits you the most.
This should work on photoshop too though there may be differences in the outcome, play with the layer modes to get the most pleasing mode.
As you can see eyes are in the end surprisingly easy to color! There are thousand different ways to color them especially if you're drawing Anime, so I encourage you to check the other tutorials that are all over dA as well and hope this helped you! Good luck