Show HN: Colorthis A API to create colored boxes

Hi HN,

This is my very first API that I've designed and deployed and I hope to get your feedback and criticism.

Colorthis is a web service for designers and web developers to create blank images for designing/prototyping.

I've originally created this for my own purpose as I find myself having to create blank images for my projects quite often and I thought since its already done, might as well let the whole world have access to it.

http://colorthis.heroku.com

Would you use something like this?