Doing a search for your error message leads me to believe that the cause of the problem is that Color doesn't conform to Codable. You have to write a transformer for Color that inherits from NSSecureUnarchiveFromDataTransformer. Inheriting from NSSecureUnarchiveFromDataTransformer will make the error/warning go away.
Take a look at the following Stack Overflow questions:
https://stackoverflow.com/questions/77831799/nskeyedunarchivefromdata-should-not-be-used-to-for-un-archiving-and-will-be-r
https://stackoverflow.com/questions/62589985/nskeyedunarchivefromdata-should-not-be-used-to-for-un-archiving-and-will-be-re
The second question has an answer that shows how to create a transformer.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags: