Change color filter to 'OR' On Uneox Template

[NCKBLK]

I'd like to change the standard 'color' filter in the UNEOX theme to 'OR'. This way buyers can select a couple of colors and browse the colors they like. In the default filter there's only an 'AND' option.

The filter needs to include products that match at least one buyer selection, but somehow I can't find a way to make this happen. Can someone help me out?