Weird color issues on C128

[bluejay]

Lately my C128’s been acting weirdly. It’s displaying odd fuzzy colors. Could this be some capacitor issue? Or maybe the cable?

 

Actually, I’ve just noticed that if I swap the chroma and luma cables around, it displays a somewhat improved picture. C64 mode looks fine now, but C128 mode displays a black background when it should be light gray. I’ve played around with the CRT controls and nothing really seems to fix it.