Select the Body of the Rocket

Locate the GeometryInstance3D Section

In the Material Override Property

Add a New StandardMaterial3D

Click on the Material Override Sphere

Change the Albedo property to a new Colour of your choosing

To the right of the Material Override Sphere

There is a tiny drop down arrow

Select that and Save the material as a resource

Call it ShipRedMaterial

You will see it in the FileSystem