I was scrolling through the internet the other day and I came across the colour wheel and how it can help you to know what colours compliment your eyes the most. Here's what one looks like:
I have blue eyes and so the coulours that suit my eye shade the most are orange/ red tones. I tend to use orange more simply because I think it is a softer colour than red and I don't like my eye shadow to be too bold, however since I have changed to more orange tones I have had more compliments on my eyes.
If you haven't noticed yet the cooler tones on the wheel tend to be opposite the warmer tones, this is because they compliment each other well, for example a brown eye which is very warm would suit blue shades which are quite cool, this is because they contrast well.