There a brown shadow (tint) in middle of the pitch when watching uhd sky football on my 4k lg tv

[Johnnyboy1950]

Its very strange...While watching Football on the sky channels the middle of the green playing surface the middle part of the pitch when the teams are playing there is a slight brown tint?

I notice when ITV OR BBC  show football games its now there?

Look forward to any help in this matter.

It only happens when thye game is being played and now when its showing  close uo of the players etc

Cheers John😁