Changing materials in sketchup free or shop

I have had a designer that uses Sketchup Pro send me a sketchup file/model but I want to change some of the surface materials to determine the best colour scheme.
Every time I select the new material from the list on the right, the paint bucket appears but won’t deposit the colour/material on the surface
Do I need to upgrade to the Shop version to be able to do this or am I missing something or do I need to get the Pro version for 5 days of use?
thanks in advance

Probably the faces you want to change color are in a group / component, so double-click on that element and then you can change the material.

Hi mihai.s
thanks for that, it seems to work on some components but not on others, I’ve tried ungrouping, exploding, unlocking but still not possible

Some may be grouped within another group within another group, and so on. Even if you explode the first one, the one inside the remaining group will still not be able to change the color unless you get to its raw geometry.

@mihai.s is right: a material applied directly to a face dominates over a material applied to its containing group or component to any level of nesting. The way to tell whether you have gotten all the way “inside” is to look at entity info when you select. If it doesn’t say face, you aren’t in deep enough yet.