How can I make my eye color stay the same?

Okay, so... My eyes have been kind of green all my life, right? But recently, I noticed they're gray, with a little bit of amber/light brown in the center, around the pupil. So, what I was wondering, is first of all...





1) How can I keep my eyes from changing back to green, or to any other color, and keep the gray?


2) Is there any way I can reduce the amber/light brown, but keep the gray?





I was reading on this, and found a few articles that mentioned how sunlight can darken the iris [in the early months of life]. Does this keep happening throughout life, or does the iris reach a point where the sunlight doesn't make it any darker?





Also, I found that certain eye drops can permanently darken the iris. Is this true?





Last, but not least, is there any way to reverse the darkening of the iris?





Thanks for the help...How can I make my eye color stay the same?
Don't be supid enough to risk your sight by putting in eye drops, no-one cares what colour your eyes are!