[earth-tattoo]

You are misreading. Basically the white paint is "fighting the sun's heat".

[foxglacier]

But that's backwards. I took it to mean the rails or the engineers are no longer fighting (coping with) heat input from the sun because the rail never receives that heat when it's reflected away by the paint.

[conorcleary]

It means the paint is fighting the energy conversion potential encroaching on the steel, in place of the steel fighting it with no covering or shield

[foxglacier]

I know what it means. "you're not fighting the sun's heat" means "the paint is fighting the sun's heat" but that's no explanation of how it could mean that. I say it's backwards because clearly whatever's doing the fighting is not the paint because it has the opposite effect. It must be the steel, as you say, or the people struggling with the problem.