I did a little more digging. That video is actually from a webinar that I did last spring, so I was curious why I didn't see that option in my current version of ENVI LiDAR either. After speaking with the engineers, it turns out that it was not working properly so it was removed until they could get it fixed. All of the classes were shaded gray, making it impossible to tell them apart. I have been informed that it is high on their list to get that functionality working correctly. For now, you should be able to view the point classifications using the option I mentioned above (via the Layer Manager after processing the point cloud).