A palette of colors on the site by example - how to implement this in general?

Question

JavaScript

Hello. Tell me, who knows) There is an original color palette (you need to click on "Select a color" under a can of paint) https://www.oboilux.ru/paints/489835 . How to implement this? What to take to help? What libraries, scripts .. The basis is clear, BUT perhaps someone has already done something similar and will give advice. Thanks in advance!
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The problem is in the implementation of a floating transparent rectangle) And, accordingly, the opening of the colors that fell into the active zone in the popup. But thank you very much for this)

Answer 1

Something like this: https://jsfiddle.net/Ankhena/r3d1djns/
then you can refine it to your taste