NIkon z8

Hello

I have a question for people who had Nikon z6II then bought nikon z8, I take shoot in jpeag no RAW. And my picture are grey they don't have nice color as nikon z6II. I tried every possiblle settings and it's still bad. Even when I do print those image they are even worse on paper.

I have nikon d850 too and they give so much better images then Nikon z8.

Does anyone has the same problem?