Every UI designer should at least know about Sketch as it’s been making waves through the online design community. This OSX-exclusive application is an alternative to Photoshop made solely for graphic/UI designers.
I first found this plugin via Designer News which explains its purpose:
It grabs the colors from the Document Colors section of the color picker and saves them as a .sketchpalette file, which you can then share with other people that have the plugin. Loading the palette file replaces the colors in the Document Colors section of the color picker for the current document. There is also a command to just clear out all of the Document Colors.
Color palettes can be saved and loaded together based on similar import/export features. Everything ties into the Document Colors area of Sketch which can behave much like a selection of colors.
New files are saved with .sketchpalette extensions which are meant solely for this plugin.
Read More at Free Sketch Color Palette Plugin for Designers