Corrie viewers were scratching their heads in confusion as Robert Preston suddenly turned grey and appeared to "age 20 years" overnight.
The Weatherfield character is currently in jail and when girlfriend Michelle (Kym Marsh) visited him in Monday night's episodes, his dark locks were almost white.
Fans of the ITV soap took to Twitter to discuss the startling transformation.
"#Corrie how did Robert get his hair bleached while he is in prison? I didn't know they had Toni & Guy in #Strangeways," wondered one, while another asked: "Can we all just take a moment to discuss WHAT THE HELLS HAPPENED TO ROBERTS HAIR?"
"Has Robert gone white from the shock of prison or has they run out of brylcreem at the prison store??" said another.
One baffled viewer tweeted: "Why has Robert aged by 20 years?"
"Blimey! Life inside must be stressful. Look what's happened to Robert's hair in just a week!" posted another.
Many viewers shared amusing pictures and video clips demonstrating their shock.
However, most people seemed to think the new look suited Robert (Tristan Gemmill).
"OOOOO heeellloooo robert ...I do like a silver fox," gushed one impressed fan, while another said: "Silver Fox Robert on #Corrie is looking good.
"Obviously, he's no Robert Sugden, but he wears that grey hair very well!"
Robert's hair saga provided some light relief on the cobbles after last week's drama, which saw both of Pat Phelan's hostages, Andy and Vince, killed off.