Doublo Aluminium Buildings and Ballast colour

[JSx]

I'm new to this game but my lockdown project is integrating my father's  Doublo three rail set as an outer outer track and modern inner tracks to reproduce a large 1945 era layout.  Can anyone help me with a couple of little problems?

1.  What is the best way to replica the colour of the Doublo aluminium D1 station, etc?  I need this so I can add platform curves.

2.  The old three rails come with tinplate ballast.  Since the modern and Doublo systems run close together, it would be great to create ballast for the rest of the layout that blends in with the Doublo colours.  I'd be grateful for ideas on the best way to concoct this.

John