I've just recently tried out this look, well I confess, it's not the first time I am trying it out. You are probably sick of this colourful bottom lash line eyeliner thing but I think it's something different and you don't really see a lot of it. Most of us just go for an eyeshadow and black/brown eyeliner look. This, however is something fresh to the table, looks more interesting and especially if you are using the color that's opposite to the color of your eyes. The contrasting color makes your eyes "pop" or shall I say stand out? So, purple will work great for green and brown eyes (hazel as well), golden, bronze and coppery shades will look amazing with blue eyes. I've seen it's popular to wear cobalt or electric blue colors on the lower lash line and I think it works beautifully with pretty much any eye color. Try navy or indigo if you are to shy to step out of your comfort zone! Good luck trying out new looks:)
P.S. This is a perfect back to school makeup idea.
The pencil I used here is Gosh Velvet Touch eyeliner in Purple Stain