YOUSU Matte PLA Filament Tri-Colors Magic Color Change Filament, Matte Red Blue Green 3 in 1 Coextrusion PLA Material, Fit Most 3D Printer, Matte Spool 1KG (2.2lbs
Chinese manufacturer (Guangzhou YOUSU 3D Technology) specialising in co-extrusion silk and multi-colour PLA filaments. Sells on Amazon under the YOUSU brand.