Attach RGB LEDs to the micro:bit
Here's another quick guide to attaching RGB LEDs to the micro:bit. They are often called neopixels but are actually WS2812bs.
I've used the Kitronik Hex Zip but you could use the Code Bug Glow Bug or the Crumble Spark. They're all about the same price. The Glow Bug comes with crocodile clips, which is an added bonus.