Watch: Optical illusion of ‘Crocs and socks’ reignites years-long debate – what colour do you see

“Under normal lighting conditions, all people see the Crocs as pink,” creators Pascal Wallisch and Michael Karlovich explained.

They noted that when put under green light, most people see the same Crocs as grey.

“However, some people – those that believe the socks are white, even though they appear green – are able to look past appearances and see the Crocs as pink, just like they did under regular light,” Wallisch and Karlovich wrote.