Reproduced on multiple OS X installs and hardware.

Prerequisites:

• A dual screen setup OS X install.

Steps:

• Launch Unity and place it on the primary display.
• Select the background colour of the main camera in order to open up the colour picker.
• Move the colour picker to the secondary display.
• Click the pipette icon in the colour picker window and notice how it works just fine when moving around on the secondary display.
• Move the cursor to the primary display and notice how the colour picker is no longer updated.
• Click somewhere in the primary display and notice how the colour picker is updated, but the colour is not picked.

Expected:

• The colour picker should be able to pick from any display - being located on any display.