Amazon.com: NC 24 PCS PBT OEM Profile Blank Black Red White Purple Pink Light Blue Green Dark Gray Keycap 1u R1 R2 R3 R4 Keycap for MX switches Mechanical Keyboard Switch R1,
R4iTT for DS v1.6 : r/NDSHacks
104abs Non-engraved Keycaps Full Light R4 Black Red Transparent Fog White Blue Purple Cherry Axis Mechanical Keyboard Keycaps - Mice & Keyboards Accessories - AliExpress
R4iTT Purple Works under YSMenu Kernel Wood R4 Kernel.flv - YouTube
Purple, Silver, Black and White R4 Unit by MarcusStarkiller on DeviantArt