Spectraflame

From Hot Wheels Wiki

Spectraflame is the name used by Mattel for the radical finishes sported by their original "Hot Wheels" cars in 1968. The finish was technically not paint but translucent colored lacquer applied to the polished bare metal castings, giving a surprisingly realistic metallic or metalflake effect, as was popular at the time on real cars.

Within a few years, Spectraflame was replaced by conventional enamel paint (including metallics) but it has been used for special editions ever since.

While most Spectraflame color names are self-explanatory, lime green was for some reason described as "Antifreeze", and light pink as "Lavender". "Hot Pink" was apparently seen as a "girls' color" and few cars were produced in this finish, ironically making such examples extremely rare and highly sought-after by modern collectors.