Adding "contenteditable" attribute to divs that are editable

First off, this is great. It's been a huge time saver and works great for my use case.

I'd like to make the suggestion to add a `contenteditable="true"` attribute to the divs that hold the color pickers where the user can drag their mouse around to edit the color. This would help provide the browser more information, but would also easily solve an issue I'm running into with a Drag and Drop component I'm also using (dragging the color picker also tries to drag the container for the color picker, when only the container should trigger the dragging functionality).

I'll likely add a PR for this soon