YOUSU Tri Colors Red Blue Yellow Matte PLA Filament 3 in 1 Magic Color Change 3D Printer Filament, Dimensional Accuracy +/-, 1KG/Roll, Work with Most 3D Printer
Chinese manufacturer (Guangzhou YOUSU 3D Technology) specialising in co-extrusion silk and multi-colour PLA filaments. Sells on Amazon under the YOUSU brand.