There is no data in API response by which I can determine the exact color of a design if fills is Figma.mixed. I am working on a plugin and this seems to be an issue that has been bothering me for a very long time.
Need your help guys!
If you’re referring to mixed fills from a text node, then that means some characters have different fills from other characters. There are text-node-specific APIs that let you get more information:
Mixed fills can exist not only on text. Here is a more extensive answer with a code example.