Smokebox colour

[Rail49]

Hello everybody,
I know that it may sound as a stupid question but can anybody tell me why many steam locomotives had their smokebox painted in silver or graphite?
Was it only for cosmetic reasons or there were some more serious technical or normative reasons?

Thanks
Gianni

[mp15ac]

The reason was that the bare metal of the smokebox would get too hot for paint (the paint would peal). So the railroads would use a mixture of oil and graphite to protect the metal from the elements (rain, snow). Mattering by the ratios of the mixture the color could be anything from silver to almost black.

Stuart

[Rail49]

Thanks Stuart,
That was a very interesting answer.

Gianni

P.S.
If you are in Arizona the light at the end of the tunnel could be the Roadrunner with a miner's helmet