Custom Resolution Utility (CRU)

[apav]

Little off topic but I'm just wondering. So if I understand this correctly, when your monitor is at its limit with the refresh rate it can handle, you may see artifacts or scan lines that look like this:

https://flic.kr/p/edF574

I've also heard of scan lines that are other colors as well. So now I'm wondering what it is that I'm seeing on my monitor:

https://flic.kr/p/mhJAVz

It's hard to notice, but they are flickering, dark, almost transparent, horizontal lines that appear when my monitor is at 120hz and sometimes also at 110hz. I notice them the most in the top corners of my monitor. Are these just another form of artifacts because my monitor can't perfectly handle 120hz? What's interesting is my monitor can even display 135hz but the colors look much darker and blue scan lines start to appear. I have been running 120hz in games, but sometimes I can notice the lines. I have a QNIX 1440p PLS.