Click the top node in the browser.
What is it that you are trying to do that you need to select all faces?
Change the color of the part I'm working with
If you have only one part (solid body) then you merely need to select the desired color from the drop-down.
You can also do this by right clicking the top node in the part browser and select Properties.
If you have multi-body, then select the body in the browser and right click and select Properties.
Similarly - you can change individual feature colors or individual face colors by selecting, right click and select Properties.
Attach your file here if you can't figure it out.
If you want to change the appearance of lots of individual faces in a single operation then you can open the appearance browser, then window select the faces & then right click on an appearance & use "Assign to selection".
As mentioned below appearance overrides can be done at the face, feature, body or whole part level.
Hope this helps,
Chris