The color does make a difference.
All sailplanes are white for this reason.

Park two Westys next to each other.
Put your hand on the white top- WARM
and then on the darker top- HOT!

On a Land Rover, there was an aluminum
panel bolted to the roof with 2" spacers. The
roof was always in the shade.

> My understanding is that all these vehicles, whatever the color, will
> achieve the same exterior body temperature. If this is true the physical
> changes to make would be:
>
> * Window tint
> - Driver and passenger door glas to the maximum legal limit.
> - All other glass to the darkest you can tolerate.
> - Adding a tinted strip to the top of the windshield.
> * Body insulation
> - This part can be scary and expensive.
> - Keep the curtains closed whenever possible.
> * Air circulation
> - Additional taxi fans.