This is an Open Source project, and the source code can be found on GitHub: https://github.com/samlanning/trello-enhancements
Customize the look of your Trello boards by enabling card background colors (taken from labels) and header cards.
You can try out this extension on the example board: https://trello.com/b/S3asr5Or/visual-enhancements-demo
To display headers, add "--" at the start and end of the text for your card.
If this card has a label, then the color of the first label will be used as the color for the header text
### Background Colors
If this card has a label, then the background color will be based on the color of the first label. If you only have one label, then that label will be hidden, otherwise you'll still be able to see all the labels displayed.