An "ultra express" post! :marioCours:
The color picker has been modified since Maya 2011 and its transition to Qt and it's now impossible to pick a color outside the Maya interface.
Actually yes, you can! And it's quite easy to do! :hehe:
You just need to select the picker, click anywhere inside Maya interface, keep the left mouse button, and drag outside the interface on the color you want.
I must confess, I have not found it myself. :baffed: