http://www.mybadmintonstore.com/shop/index.php?cPath=25_58_60&sort=3a&filter_id=10c which colour is the best?
the differences are in speed, red fastest, blue medium and green slow, from yonex red should be from 0-13 degrees, blue for 12-23 degrees and green for 22-33 degrees, so depends on the temperature of the hall, for most people blue would be good... this is due to the air resistance differences in different temperatures