Fixed Clock Widget on Nexus 4

I'm going to come across as a complete android newbie here but I can't for the life of me work out how to change the colour on the fixed clock widget.

Its on my widget list, i hold down to grab it, drag it onto desktop and it just sits there, nothing comes up prompting me to edit etc which is what normally happens with other widgets or clocks done through zooper.

I'm lost.

HELP!