Adafruit RGB Matrix HAT + RTC for Raspberry Pi - Mini Kit : ID 2345 : $24.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Flexible WS2812 RGB Full Color Dot Matrix Display FPCB – ElectroDragon
Amazon.com : AZERONE P10 Led Matrix Outdoor Waterproof Screen 1/4scan SMD3535 3in1 RGB Full Color LED Display Module Panel Board 320x160mm 32x16 Pixels (RGB-Full Color, P10-320 * 160mm) : Office Products
Amazon.com: RGB Full Color LED Matrix Panel 64x64 Pixels, 4096 Individual RGB LEDs,Adjustable Brightness,3mm Pitch, Displaying Text Colorful Image Animation Chainable Design Compatible with Arduino/Raspberry Pi : Electronics