Passing `-fullscreen` argument has odd background color

[a2]

Dear team,

I found out about the TIC-80 through this post on the clockworkPi forums. I was able to compile and run the TIC-80 myself (thank you for the great instructions). When I run it in -fullscreen mode, there is still a window around the virtual "screen" and I was wondering if we could make that black so it fits in a bit better?

If I have time I want to look into this myself but I don't know when I will have time.

Thanks so much for the great fantasy console, ~ Alex