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There are two intepretations of the color of the kettle, shiny which is removed from the original expression and black(ened).
The expression is usually best thought of as a kettle calling the pot black because it is burnt on the bottom from being on the fire and the pot points out that the kettle is also blackened - it just cannot see that about itself.
I have always seen the expression less as a statement on hypocrisy/whataboutism and more needing understand your own sense of self before that of others.
The person sending the meme is the one that is saying pot-kettle-black.
Hey! I thought I had it this week.