Tip: If you give a Muncher tile custom graphics, it will still act like a coin when a silver P-switch is active, whether it looks like a coin or not. So make sure to use ExAnimation if there's a silver P-switch in the area.
This patch allows the player to press Select during the map screen to cycle through all 8 available Yoshi colors. This changes all map Yoshi colors as well as the in-stage Yoshi's color. The choice persists across stages and will never change until the player presses Select on the map screen again.
It has hijacks but does not require freespace as I was able to find a nice chunk of 64 bytes in the stage color indices at $17C694 that are no longer used.