Well, those were my initial thoughts.
I have never tried any eyeliner variations aside from black and a dark slate grey - the other variations have simply never appealed! I'd never even considered trying a different colour to line my lids but recently, Cara Delevinge rocked electric blue eyeliner for the Giles show in LFW 2014 and I must admit, I was tempted. So I caved and gave it a whirl.
Not owning any blue eyeliner, I opted for using a bright blue eyeshadow instead, making sure it was visible on both my waterline (under my lashes) and a thick line across my top lash, but was careful to avoid it looking like normal eyeliner.
I must admit, now I've had a taste of bright colours on my eyes, I'm going to be experimenting a lot more. Watch this space, I have an unused orange lurking about somewhere...