Thanks! Took me a moment to realize how to apply this (here for others benefit): 1. Right click > Block element 2. Click anywhere 3. Change the rule to:

Thanks! Took me a moment to realize how to apply this (here for others benefit): 1. Right click > Block element 2. Click anywhere 3. Change the rule to: ##html:style(filter:invert(100%); background = #fff;) 4. Click preview and create if happy