For red/green colour blind, blue and purple are exactly the same colour while red, brown and black are very hard to tell apart, particularly if the manufacturers of the holds are different and/or colours are faded or if it's up the back area where there isn't much light (this ends up covering most climbs one way or another).
Of course all route setting at a commercial gym can't be organised around a minority but some kind of factoring of this in would make a big difference. |