For those who want to test their perception of colour, I made a little game called "What's My JND"

https://www.keithcirkel.co.uk/whats-my-jnd/?r=ARUjKP__-ve-

What's My JND?

Find your Just Noticeable Difference in colour perception. How small a colour difference can you actually see?

@keithamus got 0.0018, but I'm also on an HDR display and was wondering if that helps with getting a lower value there.
@karolherbst they're all in sRGB so HDR _shouldn't_ matter, but having a good display which can represent all of sRGB certainly will matter.
@keithamus @karolherbst on some systems, SDR is stretched to fit HDR, which can increase the gap between two colours.

@keithamus so it seems like there is an issue with the test. There are certain rounds that only have a single color across the entire page, e.g. "background: linear-gradient(to right, rgb(149, 126, 211) 24.8914vw, rgb(149, 126, 211) 25.1914vw); display: flex;"

I verified with a color picker on my desktop and it also displays the same color across the entire range.

Though I'm aware that there is just a limited range for colors, but was wondering if that's intentional behavior.

@karolherbst on one hand, I could sound really clever and say these rounds are designed to be a false test to trip up the cheaters. On the other hand I could admit that my failure as a programmer and say that these are likely rounding issues...

I've not yet decided which reply to go with.

@keithamus both would be very credible, but having a "I don't see any difference, it's the same color" button might spice this up a little...