Don’t like the “murky” look of your course cards on the Canvas Dashboard? Clean it up by removing the Color Overlay.

On your Dashboard, click the three dots [1] and then deselect Color Overlay [2] (see the screenshot below). That will allow you to see the true colors of your course images.  The course color coding will display in a circle behind the three-dot menu on the course card. (Please note: This is a user setting, so it will apply only to your view of your own Dashboard.)