Feature request: color picker/adjuster

[echadwick-artist]

It would be great to add a color picker GUI here, so we could adjust glTF color values via a GUI.

• Show color in sRGB (as it does currently, nice job btw!)
• Replace values in glTF (convert to linear on exit)
• Copyable hex code, for pasting into other apps (e.g. Photoshop).
• Eyedrop picker, to copy colors from the glTF Preview (e.g, Babylon.js Inspector).
• Color wheel GUI for easy mousing.
• HLS spinners for fine adjustments.

The following is overkill, but might give you some idea of the possibilities. In particular the wheel + triangle are helpful, as are the RGB and HSV gradients with numerical input (with clickable +- arrows for each).

[echadwick-artist]

I looked through the VSCode extensions, lots of color pickers, but no one seems to support RGB floats :(

[echadwick-artist]

I found a web tool that helps, albeit in a cumbersome way. http://davengrace.com/cgi-bin/cspace.pl