Pre-Paint UV Image with random colours according to Island Layout
Taken from the following Right-Click-Select suggestion:
Random UV color
The idea is after laying out the UV Islands, a random colour is applied to each island to better co-relate the 2D UV Image and 3D Mesh.

I thought that this suggestion would be best served from within a plug-in rather than Blender core and wanted to mention it here for your consideration.

Are you willing to contribute about this feature. (Yes/No)
I apologise, but I'm not so well versed in Python.

Screenshots [Optional]
Screenshots are in RCS suggestion.

Additional comments [Optional]
Issues to consider

• Overlapping islands
• Altering UV after painting (Auto repaint?)