Setting the colorbox opacity by hash parameter when initializing doesn't work the way like the documentation Show archive.org snapshot tells you.
$(selector).colorbox({ ..., opacity: 0.5, ... }); // has no effect
The opacity value of 0.5
will be overwritten by the inline style attribute style="opacity: 0.9"
that colorbox sets.
To manually set the opacity you have to add the following css rule
#cboxOverlay { opacity: 0.5 !important; }
Posted by Martin Straub to makandra dev (2013-12-20 14:01)