4k - YUV420 or 4k - RGB?

In the PS4 settings I can choose between 2160p - YUV420 and 2160p - RGB…

But where are the differences?

What is better for a 4k monitor that doesn't have HDR?

Why don't you leave it on Automatic?

YUV20 is particularly suitable for older TVs, RGB only works from HDMI 2.0.

You just have to test whether it makes a difference for you when both are possible.

If your monitor would be too bad you would only have limited options, but because you have one with which you can use both 4k variants, I would recommend you to start a game and then try both (i.e. The 2160p variants) it helped me too to decide.

Just wanted to know what the differences between the options are