Not sure if there's a planning consideration, but I think it looks pretty much perfect as it is.

Maybe the Everton crests are backlit in blue for night games? Or the pumphouse will be lit up in blue?

I'm not really sure where they could have incorporated blue on the outside? Can't paint the bricks blue as it's meant to mimick a dock warehouse? Cols point is very valid mind, have to keep it squeaky clean or it will look ratty pretty quick.