You can find some implementation of graph coloring algorithms at these links:
Several algorithms are linked at [http://www.adaptivebox.net/CILib/code/gcpcodes_link.html]
Optimal graph coloring via linear programming methods: [http://code.google.com/p/exactcolors/]
An efficient implementation of the RLF heuristic [https://imada.sdu.dk/u/march/gcp/rlf/index.html]
A parametric-complexity exact 3-coloring solver with yes/no witness (Web based application): http://graph-coloring.appspot.com/
If you have developed a new graph coloring algorithm and you would like to have a link here, please, let us know about.Â