Paint tool not working with layers

Hi All, I just got sketch up and have created a floorplan, I’m trying to colour the walls black and I’ve gotten most of them to be, however, it seems that there are two layers which one randomly won’t change colours, I can’t make them plain black or textured.

wondering what can I do to make colours or how to merge layers?

Layers can’t be painted. Layers in SketchUp are visibility controls for groups and components. You would normally paint materials or colors on to faces within the groups or components. (Those faces would should always be on Layer 0) If you are unable to apply materials to certain areas in your model, that would generally imply that there’s no faces.

Perhaps you could share your SketchUp file so we can see exactly what you have going on and help you get it sorted out.