Issue: Style Variables won't save

So, I'm trying to style the wiki to match my theme.

I go to the VW control panel -> Styles -> Variables -> CB-XEN (name of my theme, which is a child of another theme) -> Wiki Pages -> Content Blocks. Default value is a light yellow. I try to change it to any other value, and it removes the yellow, but won't drop in the new value. It just removes the default value until I reset the variable back to default.