Set Philips Hue lights based on dominant colors of an image.
RGB to xy conversion: https://github.com/PhilipsHue/PhilipsHueSDKiOS/blob/master/ApplicationDesignNotes/RGB%20to%20xy%20Color%20conversion.md
Dominant color identification: http://charlesleifer.com/blog/using-python-and-k-means-to-find-the-dominant-colors-in-images/