Interesting. It helped to rock my screen back and forth, since the differences were *slightly* more noticeable at different angles. That being said, I was only certain of one, and only saw any discernible difference on maybe three of them, yet I still got 11 right. I found it fascinating that my brain was able to work out most of these correctly without me being cognitively aware that there actually was a difference.
crazy how some immediately pop out as different and some my brain refuses to accept they aren't all the same - i wonder if we all find the same ones harder? for me 6 8 and 11 were easier
If I look now again, 6 is the most obvious one. I got that right and in quiz statistics it is way above others with about 90 % recognition. RGB notation would tell, why it is the easiest.
I got 8/15, but saw the real difference only in two or three cases. Expectation value is 5, so most of my correct answers were more luck than vision.
On my perception the differences within bars from left to right were huge compared to differences between bars.
It would be interesting to know all these colours in RGB notation, how big or small these differences objectively are.