Move Colour to utils.

Change-Id: Ibf9936e6cf89ebbe1243e1c32596bc726bebc5ce
Depends-On: I73c10f367e5972031d1c9b0871c4cb9043008bec
Reviewed-on: http://gerrit.dmdirc.com/3859
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>