Alclad II colors

Duraluminium is an alloy of aluminium that was used for Landrovers, and a number of other vehicles and aircraft skins in England and possibly other countries. The colours are almost identical as are most aluminium alloys, with the biggest difference between them being the way Americans spell aluminium wrong.
If the alloy is anodised, then the colour may be different with a range of blues, golds, etc available. Aluminium will oxidise quiclky and build up a surface layer of oxide coating that looks a little white compared to a mirror like finish.
In current times there are over sixty common alloys of aluminium made by the larger companies, and a number of other specialist ones for special purposes. Some of them are used for corrosion resistance and some of them have higher strength, some of them handle heat better than others. Pure aliminium is lighter coloured and very soft and silicon is added to many castings at about 10 to 14 percent to make it harder while extruded parts like spars are about 1/2 to 1 percent silicon. The silicon will make the alloy a little darker but most people will not notice this. Other elements like magnesium, copper, manganese are added to improve the properties of the alloy.
As you have two colours available, I'd be inclined to paint cast parts like brackets in the darker colour and sheet panels in the duraluminium colour, but this could be adapted to suit your preferences or any notes you have after viewing real equipment displays. Newer equipment will be a little cleaner while used equipment will be a little more weathered.
Hope this helps, Peter

I think if you spray some of each of them, you'll find they're similar but not identical. Using these two shades, along with some of Alclad's other ones, allows you to make subtle differences between panels on a natural metal surface. Pip Moss I used to feel cheap 'cause I had no signature.