If you want the green to pop out more you need to wear warmer browns, dark reds/burgudy/purples. It's all color theory. The opposite of green is red, and if you want the green to stand out keep that in mind. You can even wear green eyeshadow tastefully and that will pop the green out as well.
color contacts change it in a obvious way. but I think the darker the eyeliner, the darker the area around the eyes will make the eyes pop more/ have more light colors due to the contrast. maybe you using too much light foundation.
Then again I'm just a guy who observed girls and never studied make up and the opinions by those 3 girls makes a lot of sense.
Your moods have an effect on your eyes. I notice some eyes get vividly brighter whenever they are angry. when they are sick, their hues are softer and pale. Its more obvious in blue or light brown eyes.