Alexandre,
I believe Buckeye was keen to learn what brand name (e.g., Humbrol, Testors, Tamiya, etcetera) and which specific color (colour) name (e.g. "NATO Black", "Rubber", "Oily Black" or the like) was useed.
As an example, many in the US rather like using Testor's Model Master "NATO Black" to paint the solid rubber tire (tyres) on tracked vehicle road wheels.