Do you have a link to a source where the color accuracy of an IPS panel would go down if you ran it at 120Hz vs at 60Hz. That seems quite counter intuitive to me.
No, it's just obvious when you understand how the technology works.
Pixels don't switch instantly they take some time to change from the colour of the previous frame to that of the new one during this period they're displaying inaccurate colours, eventually they reach the intended colour and then stay at that colour until the next frame refresh occurs when the process starts again.
Visually how that appears on the screen during motion is what we refer to as ghosting. On a contrasting desktop if you drag a window around you see a trail behind it that's like a blur, because you're seeing this pixels swap from one colour to the next over some short period of time, that's visually very obvious to us especially on panels with high pixel response times.
Now that's actually happening across all of your monitor where ever there's changes in pixel colour which typically in games is more or less constant across most of the screen. Colour accuracy in one sense of the word is a ratio of how much time the monitor is displaying an accurate colour vs an inaccurate one. If your pixel switches in 1ms it has inaccurate colours for that 1ms but if your refresh rate is say 60hz it means each frame is displayed for 1000/60 = 16.6ms So the pixels has inaccurate colours for 1/16th of the time.
If you run that same panel at 120hz that's 1000/120 which is 8.3ms and now suddenly it's ratio of inaccurate to accurate is much worse it's 1/8th of the time is spent at the wrong colour. If you keep pushing that to say 4ms pixel response time at 165hz which is 1000/165 = 6ms you're talking about 2/3rds of the refresh is spent at the wrong colour
That's the reason we've not historically had high refresh rate IPS monitors because IPS technology has always had relatively poor pixel response times, something like 4x worse than TN over the years. The technology to drive panels at high refresh rates has been around for decades, we've had 120hz+ TN panels for a long time but historically never IPS, until basically recently. That not an accident, it's because panel manufactures understand that image quality suffers when you push slow panels too fast. As pixel response comes down we can make faster panels and that's great, the moment they have a 1ms IPS panel at like 120hz or above then I can gurantee you I'll be the first person in line to get one, I like high refresh rates like many other gamers I just not prepared to suffer a soupy inconsistent mess to get it.
I don't know why you are going on about colours, the colours look great on the high refresh rate IPS monitors, significantly better then TN screens
The best response I can give to this is probably in a context you'll be familiar with. Which is that many gamers, especially console gamers, will argue that 30fps is enough or that 60fps is enough, that you don't need 120hz or 144hz or 165hz or even 240hz because no one can tel the difference. Yet you clearly can, so can I, which means they're either ignorant (which is typically the case) or in some circumstances that their vision isn't very good, everyone's vision is impaired to differing degrees. I see your argument really no different from theirs it's just about colour rather than speed.
You can't just push panels at arbitrary speeds with no trade off, as the pixel response time and refresh interval approach one another the colour accuracy decreases and that's a sliding scale. What you prefer is a personal trade off, not just because our perceptions differ at a biological level but also we weight the relative things based on what we care about. This is why competitive gamers who care about response time will sacrifice colour to get it by buying TN panels and designers who need maximum colour accuracy for their design work will only work on high gamut IPS displays and happy to do that at 60hz. I'm not denying your personal preference or saying mine is better, all I'm saying is that fundamental trade off exists and that by getting a high refresh IPS panel you're getting speed at the cost of accuracy. Now that might be a preferable trade off for you and that's great, but to deny it's fundamentally a trade of is just mathematically false.
And beating a TN panel in colour accuracy is not hard, if you know how their 8 bit colour works, which is fake, it's actually 6 bit colour with a hack to use averaging (2 bit dithering) then yea beating that isn't hard, they're literally the worse panel type for colour. You could stab yourself in the eye with a pencil and you'd get more vibrant colours.