why do my eyes pop with certain hair colors?

So I noticed when i dyed my hair brown my eyes didn't stand out like everybody said they would. I have bluish greenish eyes. but when i changed to a blonde they stand out more? why is that? im really curious. I want to change my hair color again to a darker blonde and i want my eyes to stand out. If anybody has any suggestions why the reason of my eye popping for certain hair colors and what hair color should i try next. Thanks and sorry this question is a bunch of questions. :)