One for all you derv lovers.

[Poodle]

The temperature reactive paint would be just as insulating when clear as when black.

You don't want black-painted intercooler piping as under-bonnet temps will be higher than that of the intake charge, so you'd be heating it back up again. What you've described with the painting the sides of the intercooler is probably the only benefit you could gain from this, for this application at least.