Thanks, now I got the config. I didn't notice anything special with it and I'm no config expert, so I'll give you some mechanical ideas that you can try one at the time.
- Switch injectors in pairs from side to side. If the exhaust color change the other way around, faulty injectors.
- Fuel lines seem to be connected in series, which means other side gets served first. That sometimes can cause pressure difference at the injectors, so for testing, invert it, so that you're feeding the opposite side first.
- Maybe some problem with the injector outputs, change the wires from side to side to see if that is the case.
When testing individual cylinders at idle I usually over lean the mixture so much, that one or several cylinders cut out and then use IR meter to see which cylinders are colder and have a problem. Testing that way might be faster than waiting and looking at the port color after every change.