Yes I struggled coloring this (because I need new glasses and my current ones are an absolute mess). No I don't have regrets

Anyway to explain my reasoning with this: I decided to make Simon a melanistic bengal cat (here's a picture of one). Initially I was considering making him a melanistic leopard or jaguar, but domestic cats are the only cats with slit pupils (which Simon notably has in his sprites), so I opted for the next best thing. A melanistic bengal, which would similarly have slightly visible markings and rosettes.

Aside from me just having a habit of giving non-furries the same fur color as their human counterparts' hair, I thought making Simon a black cat would work with his character and what his original design was meant to convey; a sense of evil or bad luck. Where I'm from (the US) black cats are considered bad luck, so I thought it worked really well.