style prederences: more robust color retrieval

Change-Id: Ia0938b536f90acdfbfcf9332f4e047b1883af130
Reviewed-on: http://gerrit.esdi-community.eu/3196
Tested-by: Jenkins <sitemple@igd.fraunhofer.de>
Reviewed-by: Simon Templer <simon.templer@igd.fraunhofer.de>