What makes chrome or chrome-plated material difficult to paint?

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The simple answer is obvious but I am looking for a more in-depth chemistry answer to the question. I am not interested in what paint to use or what functional additives to use. I just want to understand why chrome has a window or time frame when you are able to paint it sucessfully fresh from plating and unsucessfully after 12 hours or more storage.
Many thanks.

Lucy Lim
coating - Sydney