.card-primary, .card-header, and .card-inverse don't work well together

Created by: RyanZim

The docs say:

Background variants

Cards include their own variant classes for quickly changing the background-color and border-color of a card. Darker colors require the use of .card-inverse.

Using a background variant does not affect .card-header, however, .card-inverse does. This results in unreadable text. The same goes to .card-footer. See JSFiddle: https://jsfiddle.net/uxcuem8t/2/. (There is text in the header & footer)

I'm not sure what should be changed here, but something should be done.