Thief
Thief is a node-friendly port of Color Thief, using node-canvas under the hood.
This experimental project is no longer maintained (and has no tests). Check out get-image-colors, which is maintained, has tests, and has no non-node dependencies.
Install
npm install thief --save
Usage
Cairo has a few dependencies. You'll need to run the following to develop with thief on a Mac:
brew install cairo
brew install jpg
Check out rainbowbot, an open-source Node.js web app that uses thief.