GH's colour slider does not function correctly (i.e. the sliders themselves don't appear) when modifying the colour of a global template's card.

I attempted to change the colour of a card in the 'Card Styles' section of the global 'Project Templates' section (from the JIRA admin console) and the 'colour slider' feature had no sliders.

This is not a problem when modifying the Card Style of a specific project. Only Global Templates seem to be affected.