Yes! you can apply appearances in Composer directly (although the process is different) or import appearances applied to a SOLIDWORKS file into Composer.

The task pane was probably disabled on accident The help file goes over how to turn it on and adjust it goeng.io/rf1Beb

This is a hard question to diagnose through the comments section here. To really know what is going on we would want to see the issue. The best next step is going to be reaching out to your local VAR and their tech support team to go over the issue.

​@@goengineer Hi. We have a similar issue. For explain the problem, go to 5:53. In that frame, you see the part you colored in blue, overriding the red part color. Ok, all clear. However, see that you highlighted just the top face (in the frame is the cyan one, the selected one). Let's see I want to color only that face in blue, leaving the rest of the part red (and I want to do it in assembly enviroment, ie. I don't want to color the top face in my part, only when used in the assembly). APPARENTLY, it seems impossible to do that. If I select a face, SolidWorks save the color to that face IN the part, not in the assembly.

A body is a single contiguous solid, a part is everything in this file and that may include multiple solid bodies, surface bodies, and reference geometry. Most commonly a part contains only one body but that does not have to be the case so this allows us to have different appearances on different sections of the model so long as they are separate bodies.