A color toner is added, so it becomes a color-changing PLA filament that presents different colors if looking it at different angles. Flashforge color changing filament is made of a reinforced and toughened modified material.
1111 3D Printing Filament Mirror Chrome Angle Change PLA Plastic Wire Rainbow Gradient 1.75MM 1KG - AliExpress
Inland 1.75mm PLA UV Color Change 3D Printer Filament 0.5 kg (1.1 lbs.) Spool - Gray-Natural - Micro Center
What's Bicolor PLA Filament and how to select the best bilcolor pla?
Gsun Dual-Colour Silk PLA Filament – Bits4Bots
Heat Color Change PLA Purple to Red PLA Filament 1.75 mm 1KG 3D Printer Filament Spool Color Changing with Temperature 2.2 lbs Temp Color Changing Filament PLA 3D Printing Pen Materials
Pla 3d Printer Filament Triple color Silk Pla Filament 3d - Temu
3D Printing Filaments: Choose the Best Type for Your Project
PLA Filament Pack - 6 Satin Colour - 1.75 mm - 6 x 10 meters - 3D&Print
White Green MatterHackers Quantum PLA Filament - 1.75mm (0.75kg)
Tricolor Pla Filament 1.75mm Triple Color Silk Coextruded 3d Printer Consumable Gold Green Purplish Red
Inland 1.75mm PLA UV Color Change 3D Printer Filament 0.5 kg (1.1 lbs.) Spool - Natural-Purple; Dimensional Accuracy +/- - Micro Center