The Dana

Clean-up crews worked at a Shrewsbury bridge which was targeted by vandals just hours after reopening following an 11-month renovation project. The .graffiti artists had painted their tags on the Dana Footbridge which links the Castlefields area of Shrewsbury to the railway station and the town.
Engineers completed extensive steel work repairs on the structure as well as repairing and replacing timber panels and supporting beans and brick work. Windows were also replaced on the grade II listed footbridge and the deck walkway has been renewed with an anti-slip surface and the structure has been repainted.

What I cannot understand is why a slightly different colour of paint was used to cover the graffiti.