There are 3 primary areas which allow for a huge amount of tweaking. The top zone, Material to Replace, is where you can target your materials based on selection, model or component along with highlighting these materials using construction lines selections or layers.
The clever part of Coloured Layer is that it will temporarily create a new layer called _FINDER_ and assign the object to that layer. This means in complex models you can concentrate on where you need to make changes. As soon as you toggle Coloured Layer off the object will return to its original layer.
The centre zone, New Material, contains your applied materials and is used to swap materials out based on what you select in the top zone.
The bottom zone, Apply To, is where you get to fine tune your material replacements. Whether you want to completely swap materials on every element or just target components. You can tailor the replacement precisely without having to dig through nested elements in the SketchUp workspace.
Material Maintenance is one of those true gems that everyone needs in their toolset. To get a complete guide to using Material Maintenance for SketchUp head over to KeepingMyHandIn.com where you can find the .rbz file and some solid instructions.
You can watch this video below to see an overview of what Material Maintenance is capable of.