commodore 64 CD4066

[Zac67]

[digging out schematics]
The 4066 (U28) is just for multiplexing the paddle signals (two ports to a single SID port) and has no connection to video output. I've never had a problem in sourcing the chip (up to ~10 years ago) though. I've just checked and it's still widely available ("CMOS 4066 DIP").

If color is lacking from both RF output and DIN plug S-video output, I'd guess it's either the VIC or one of the Q4, Q5 or Q6 transistors (all PN2222)

If the problem is RF only the modulator needs to be replaced. I think I've got a PAL type somewhere, but would need to do some searching...

[Zac67]

If you need a composite style signal, use the chrominance part (pin 4 instead of 1) only - lacks a bit of contrast but is fine otherwise. However, if your TV supports s-video, connect both signals to get the best quality possible.

[Zac67]

It does work on the 64. I've been using it that way for ~8 years with a Philips monitor (1084 clone).