Thanks for the reply.
Yes, I think somehow the console is stuck in PAL for 240p test suite. I've already tried changing video modes in main menu, 240p/480i are all in b/w, 288p/576i are in b/w too and image jumps (which i think is normal as my CRT is 60hz NTSC only).
I also tried to disable PAL modes in settings and restart, still in b/w. Also tried to delete 240p suite folder on sd card and reinstall it, still the same.
Checked in any region changer and wii's video mode is indeed set to NTSC, and system menu/homebrew launcher and several 240p emulators all run properly.