Hypercolor T-shirts were huge in the early 90’s. They were completely unique for their ability to change colour with heat.
They were manufactured by Generra Sportswear Company of Seattle and marketed as Global Hypercolor. They contained a thermochromic pigment that changed between two colors – one when cold, one when warm. The shirts were produced with several color change choices beginning in 1991.
The effect could easily be permanently damaged, particularly when the clothing was washed in hotter than recommended water, ironed, bleached or tumble-dried.