Mac To Windows Part 5: Colour

I have posted some of my artworks elsewhere on the net but I didn't get a whole lot of attention.
Now I think I might know one reason why: Color (or "Colour" as I was taught to spell it)

I have now both Mac and Windows PC running on exactly the same diaplay and can switch betwen them at will.  This brought me to compare the images on them.

Here are two versions of exactly the same image as dsiplayed on Mac:

 . . . . and now on Windows:

( Photos taken with my phone )

Somehow in Windows, the image has become darker by about 20 percent with a yellowish tint.
How the heck does this happen? What can I do about it? I just calibrated my display according to Microsoft, so it should be all perfect, right? Please note that this is a brand new 4K screen with 10 bit colour.

This is where I realised that other people viewing my work on PCs see it like that and then go "Aaaah, it looks dark and crummy" and they are right.

I am a bit puzzled as to what to do now. If all of my work so far has appeared like this it is time to rethink my methods. . . .but which way to go? Should I adjust the Mac so it looks darker or lighten the PC? Are either of them colour correct, whatever that means?

Any suggestions gratefully appreciated.

Yes, there are web pages about this but usually they ignore this and go on about photography which is not this.