Speaking as a Mil QHI, I have to thank the civil police heli force for applying the yellow/black colour scheme. When the 350 fleet was used to replace the venerable Gazelle for tactical training for the AAC in Devon, the flying complaints dropped to zero, can't imagine why!
On a more serious note, a potentially serious airmiss was averted in LFA1A due to the late sighting of a 350 lifting from a "confined area". The GR7 pilot commented that the only incling he had was the flash of yellow that he saw allowing him sufficient time to react and avert disaster.
But this is just my experience, thanks for taking the time to read this missive :-)