RHSL Color Picker
RHSL is a lightweight color picker that uses the HSL color space, and alternatively supports HSLuv. It's made to be very easy for developers to implement on their website, and also very easy for the end user to utilize.
After adding the color picker's files to your webpage, you only need to add the "rhslcolor" attribute to any <button> or <input> element to link it to RHSL. More information below: