Use ColourManagerFactory

Change-Id: If1bc20d15561584c9296ad10f04957efb51c5966
Depends-On: I6ef45d10a4fe862854702eee671114ee09f01d4d
Reviewed-on: http://gerrit.dmdirc.com/3867
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>