Just a heads up that HTML has native colour pickers: <a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/color" rel="nofollow">https://developer.mozilla.org/en-US/docs/Web/HTML/Element/in...</a><p>Pros:<p>- 0 bytes to download.<p>- No js required.<p>- Familiar to your users.<p>- Allows using an "eye dropper" to pick any colour from the screen on most platforms.<p>- Allows user to save/recall their favourite colours or schemes (on some platforms).<p>- Localized.
Here's a color picker I made a few years ago <a href="https://caub.github.io/color-wheel/demo/" rel="nofollow">https://caub.github.io/color-wheel/demo/</a>