What colour

A walk we often do crosses over  the river to the park, I had  never taken much notice of the decorative flowers on the bridge but after seeing the Yorkshire poppies it must have struck a chord with me. Most of them on this bridge were blue but this one was  red.
Not sure if they were all once red and the colour has warn off or has someone been adding colour to it. Ashamed to say I honestly can't remember noticing before.