Added a new css entry (.unstable) and changed getStatus() to return an unstable string. Currently the colors for unstable and claimed are identical which is probably not ideal. I'm currently working on a slightly different color scheme on my local copy (same as this but claimed is orange, and unstable is yellow). I might submit a seperate patch for this once I'm happy with it. Might be nice to make all the colors configurable, I'd be happy to give this a go.

Addresses:
https://issues.jenkins-ci.org/browse/JENKINS-10614
https://issues.jenkins-ci.org/browse/JENKINS-9772

diff taken from: plugins/radiatorview/src. Let me know if you need anything else