Kobi needs to paint a wall on the estate, but he can't decide which colour to use. Mali, Sam and Bella aren't keen on Kobi's options and are very keen for him not to use the grey from the leftover tin. They search the estate to find a colour to inspire Kobi, but in the end they decide to invent their own brand new colour. Unfortunately, attempts to create a new colour result in a horrible muddy brown mess. However, when Mali accidentally makes a messy paint mark in the kitchen, Bella is inspired to propose that they paint a mural.

When Mali and Zainab deliver some food to their neighbour, Mrs Richards, she tells Mali all about the routine sounds that help her work out what's going on around the estate. Later, when Sam and Mali discover that Bella has used up all the blank paper for their school project, Mali has an idea. Inspired by Mrs Richards, Mali gets his friends to help him create a picture of the Apple Tree House estate using only sounds.