I've heard them talk about the grey scale thing but I had assumed that applied when I put my character in a scene so I would put light character on dark background or dark character on light background. I didn't know I should have applied that to the character design as well. I didn't even consider the silhouette! I haven't done the character design course yet as I'm still working through the basic level classes. Wow there's a lot to think about. I'm pleased to have finished something though!