Hex Color Picker is described as 'puts an extra tab in the system-wide color panel. Instantly see the hex color code for any color, and edit it just the same with a number of shorthands' and is an app in the Photos & Graphics category. There are more than 50 alternatives to Hex Color Picker for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and iPhone. The best alternative is Just Color Picker, which is free. Other great apps like Hex Color Picker are gpick (Free, Open Source), Instant Eyedropper (Free, Open Source), gcolor2 (Free, Open Source) and ColorZilla (Free).