ugh. Robbie Coltrane ;_____; that quote was the first thing that I thought of as well when I heard of his passing. Thank you indeed, Mr. Coltrane.
Black is such a hard thing to work with, so I don't blame you for the white face kitty. I've found that using dark grey/greys/ to lighten and shade help with that. Granted I have not worked with colored pencil in ages but...something maybe to play around with in the future

I'm discovering my appreciation for layering greys with my markers too
also, sunshine, I feel like this is a universal image that we all drew as kids and it is WILD. Who told us to put smiles and eyes on a sun (I always did sunglasses)