SNES RGB Cable Problems

So I got a really cheap SNES RGB cable and the colours were way too bright. In Super Mario All-Stars I was playing Super Mario 2 and noticed at the end of the first level at Birdo, the sky was white along with the clouds. Changing the contrast on the TV didn't correct the colours and it looked fine on RF so I took apart the cable and took off all the 220uF capacitors and instead added resistors inline with the red, green and blue inputs and changed pin 9 on the SNES to pin 7 as sync on luma to get rid of the checkered image I had on the LCD TV's. After doing all this it's much better and the sky is the right light blue colour now. The screen still shakes up and down on LCDs but I think that's just because of the nature of the newer TVs and 240p signal.

Anyway when I tried it on my 14" Beko CRT I thought that looks ok, but then when I got to the press start part in SMAS the screen turned really colourful, like extremely over-saturated. I changed to RF and the problem wasn't there anymore then I changed back and the colours seemed ok again. That's when I thought ok well I left the RF cable in the TV at the same time and thought can that affect it. I removed the RF cable and within seconds it went extremely over saturated again. Plugging the RF back in makes the colour go back to normal within a few seconds so I'm assuming this is a grounding issue.

Which pins are a must for grounding as the only grounded pin in this cheap cable is pin 18 which says RGB blanking ground. Should I make sure pin 17 is grounded too or would this make a difference?

Also pin 18 and 20 has a 220uf capacitor between them which I removed thinking that was the problem but it wasn't.

I have more SCART cables I can use the heads off instead if this one it just way too cheap to work properly. Tbh I didn't even see a ground cable as 21 which is more likely what's wrong actually now that I think of it.