How do you use color coded tilemaps

Could I use a step by step to use this

We have some documentation here: https://arcade.makecode.com/courses/csintro2/tilemap

Is there something you’re trying to build that can’t easily be done with normal tilemaps?

I’m kinda lazy and making a really big chance game but I don’t want the walls for more work so I decided with the code color blocks and the walls on or off.