How to set a colour tag to a card?
To set a colour tag to a card, first, open the Card Details and then click Add colour tag located at the top left corner of the panel. Choose up to five colour tags from the drop-down list.
To change the text of a label, click on the Edit colour tags button at the bottom of the drop-down list. Then click on the necessary tag to change its text and then hit Enter on your keyboard. You can also remove text from the label and save it as empty.
Tip: Remove toggle from a checkbox opposite to colour if you do not want to use this colour on your board. This colour will not be displayed in the drop-down list of colour tags.