Hmmm i thought recently to use two layers for color, because of some shading/tone that was not satisfying with a singel color tone... i yet did not try it cause i need more basic understanding of layer's operators on my software, but i think this is a solution, i just also need to think of what knd of secodn color may benefit to the first according to tone however in my actual system, there is a strange thing: two "similar looking" color tones that are yet different un the values of rgb (same for eyes, not same for computer)e really gives out strange and different results... by now what i need is tutorials and explnaiations about good iris pattern/detail because i need to improve this :(