One social media user claimed to know the joker behind the prank, writing on X: "My mates just texted me there. He bought 10,000 blue flares and spent the last 4 weeks taking the blue labels off them and putting red labels on them. I hope he sells the f****** lot."
The flares were evidently picked up by more than just a handful of Reds fans, with blue smoke seen throughout the pre-match jubilation.