After a comprehensive study by the RAF it was found that the colour which

was most conspicuous in a wide variety of daylight conditions was black.

The colour which was least conspicuous was, you guessed it, white or light

grey. Strobe lights are not very effective in bright daylight conditions

and when do we do most of our flying? When the sun shines.

There are very good technical reasons why the top surface of a glider must

be white but does the underside have to be?


I recall a similar study by the FAA (which I can't locate at the moment) in which they found white was the color easiest to see against blue sky. White reflects the most light back to the observer.

I would lean towards a white flashing strobe myself. This should be very easy to see.