Mechanochromic luminescent (MCL) materials change their color in response to a change in their environment, like pressure and temperature. To date, most MCL materials only change between two colors, limiting their applications. A international research team has developed tricolor-changing MLC materials. Not only that, the developed materials exhibited efficient thermally activated delayed fluorescence (TADF) and allowed high performance organic light-emitting diodes (OLEDs) devices.