Yes, it was obvious that the icons are clickable, and I did see the color picker - but it was a very simple color picker, just a grid of color tiles. Now that you mention it, I realize that there is a second, more advanced color picker, available behind the "+" button in the first picker, and there I can type in hex. I am guessing that the features of the color picker are determined by the browser, and not by your site?
You click see the (?) icon to see the summary of the algorithm.
The tool generates unique, meaningful names for any RGB color using a combination of color properties. Every name is unique and reversible - you can convert any name back to its exact RGB color!
In the book 48 Laws of Power from Robert Greene, Law 13 addresses this. If you held them by past deeds people will feel that they owe you something and nobody wants to owe anything to anyone. It is better instead to show them what they have to gain from now on.
If you click on the color pallette icon, that brings up a color picker and you can choose any hex.
Is it not obvious that the icons are clickable?