You can only change the color for Dropdown type Custom Fields. For that type, you can open the Custom Fields settings box and click on the gray box next to each dropdown option, where you'll have the ability to choose a color for each type:
Hello Community! My name is Brittany Joiner and I am a Trello enthusiast and Atlassian Community Leader. In this video, I'll share my favorite Trello templates. Templates mentioned in ...
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