Grubshka

Allow dragging on picker and slider

2

It should be quite easy and user-friendly to allow dragging on the picker and the slider, listening to "mousedown" and "mousemove" instead of click.

Allow more that one picker per document

1

Only the first picker of the document is working, probably because of the "id" used for the gradient. You could handle this by adding a counter in the ColorPicker object,...