It would be very useful to have an ability (to assign a key shortcut) to temporal switching to the Color Picker.

For example, I'm working with a Fill Tool, making a gradient fill. Selecting a fill color node I need to apply some color from the photo, etc. Pressing shortcut key -- switching to the Color Picker, after applying a color I have Fill Tool back... The same is very useful when working with other tools too.

Thanks!