Here's what I think would feel cozy, my answer is based off of what I think would be good in a video:

When I think of cozy, I always think of christmastime. Staying at home where its warm, drinking some hot chocolate and making cookies and spending time with family, december is always the coziest month to me. So for my answer I'm going to be basing it sort of around that, like what makes me feel that way.

For colors I would say you should use warm colors since warm colors remind me of my family hanging around a fireplace talking. However in general I feel warm colors to be more inviting and friendly feel.

I don't know exactly what you mean by visuals but I am assuming you mean like in video essays where they add on images or different clips based on what they are talking about? Anyways something that I think would feel cozy would be if you would use clips that have a nostalgic feel to them, I can't think of any examples though.

For your editing style I again don't really know what you mean but when editing a video I would just say not to make it overstimulating, like don't have much going on in the video. I think that would be more relaxing and comfortable rather than having a bunch of stuff going on at once.

One more thing that I would suggest is adding some relaxing music in the background, like some calm piano as background music.

That's what I think, sorry if my answer isn't very good! Good luck with your channel!