It's weird phenomena right here.
When i was 16 years old, My eye color was brown. On my 17,5 It lightened a bit. And this week i realized on my friend's mirror green colour arround my iris, and the centered Brown that has been fading away.
Is that happened to most of people?
Isn't this procedure supposed to be @ young age?

My eyes are green. They used to be more blue, but now they're more green.

Eye color is dependant on pigmentation. Sometimes, the pigmentation in some people may change. I've read that this happens to about 10-15% of all caucasian males as they develop. Their eyes go from a brown to a hazel. Whilst abberant, there is nothing to worry about.

Yeah they can change slightly with time.
Also, don't forget that we perceive colors depending on the quality and color of the surrounding lights. For instance, if you were to take a blue pencil and place it under a red light, it'll look violet to your eyes.
But the most interesting effect is perhaps heterochromy:

omg my aunts dogs eyes are like that

My music teacher has eyes like that dog but theyre green and brown

Well, my eyes are blue/green, maybe it's just imagination, but on some days they seem to be more blue and on other days they seem to be more green. :|

same as me

Well for some reason i want my eye color to be changed

Meh my eyes were dark blue 7 years ago, now they are grey-ish blue.