On the complicated issue of tyres I looked into it when I was sculpting the Austins.
It's sort of a sliding scale roughly 1904 is when carbon was experimental added to tyres in the UK ( the empire owned the lions share of rubber production.)
1910-11 commercially available black tyres in the US ( being where the majority of the carbon oil was produced. )
Around late 1916-17 Good year started produceding black tyres. The majority of BEF tyres were a light grey. Often with Soot buffed into them.( sooty tyres being thought of as the original carbon source/idea.Then carried on as a 'way' to increase the longevity of the tyres.) Then it's all boring bits about adding webbing in the production process and rubber quality ,costs, time,supply chains and so on.
In a really loose rule of thumb the earlier the lighter the later the darker. ( Not necessarily black.)
It was possible that some early vehicles my have imported black tyres,Just as its possible for some later vehicles to have different coloured tyres or wheels depending on what's available from stores.
If your feeling clever then white walled tyres are more realistic as the areas between the tread sections tended to stain and age darker than the wall of the tyre and on roads the treads could wear back to white. They can look seriously garish to the modern eye.