An empty colour field can't be set to #000000 via the colour chooser popup.
Uncaught RangeError: Maximum call stack size exceeded
at RegExp.[Symbol.replace] (<anonymous>)
at String.replace (<anonymous>)
at U (jquery.js? [sm]:4216)
at V.get (jquery.js? [sm]:4297)
at Object.trigger (jquery.js? [sm]:8711)
at HTMLInputElement.<anonymous> (jquery.js? [sm]:8793)
at Function.each (jquery.js? [sm]:381)
at b.fn.init.each (jquery.js? [sm]:203)
at b.fn.init.trigger (jquery.js? [sm]:8792)
at s.constructor.<anonymous> (ColorInput.js:40)
#000000.Screenshots:
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Press enter or click off colour chooser
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... and thanks for making a CMS that is a genuine delight to work with!
The reason that’s happening is because color inputs are set to #000000 by default, if they don’t have a value attribute. So the input isn’t sending a change event when you close it with #000000 “still” selected.
I’ve worked around this for the next release by updating the text input on the color input’s input event rather than change, which will get fired even when the color picker is still visible. You still have to get it to register that you want #000000 by temporarily changing the color and then changing it back, but it’s a bit easier than selecting a different color, closing the color picker, and then (re-)selecting black.

That JS error was unrelated, but it’s fixed as well now.
Craft 3.6.5 is out now with that change ✨
Speedy. That works great in my opinion. Thanks 👌