Just a different way of choosing color values.
If you don't know, HSB stands for hue, saturation, and brightness. And HSL for hue, saturation, and lightness. They are two separate methods of choosing color, but similar, I would be happy with either one.
One of the things I like about using the HSB/HSL inputs is that it feels intuitive (especially compared to Hue box that we use now).
If it can be done, I would leave a choice to user to select which way they chose color.
Examples:
http://hslpicker.com/
http://colorizer.org/
(HSL and HSV/HSB section)
Thank you,
Zaovar.