This question is in reference to Atlassian Documentation: Customising Cards
I have tried this many times! It seems that the card itself won't have a background colour change BUT a thin vertical strip next to the card will have a colour change. How can we change the entire colour of the card itself?
I wish I could attach a screen shot to show you! A friend of mine from a different company used "hacking kanban board with a bookmarlet" to achieve this.