Ireland and Wales will play out their Six Nations opener in traditional green and red colours this weekend, just a few months after World Rugby released guidance on kit clashes which affect colour-blind supporters.
The governing body published guidance on colour vision deficiency (CVD) last autumn - led by chairman Sir Bill Beaumont, who himself suffers from CVD - and warned that a clash of green and red kits can lead to fans with colour blindness "switching off" as they struggle to differentiate between teams.
However, Wales and Ireland's kit are produced in two-year cycles - meaning they would need two years' notice to act on such guidance - and neither has a suitable alternative jersey which would solve the problem for this weekend's clash in Dublin on Saturday.
