ismy.blue is a weirdly fascinating website whereby it shows you a page that has a background colour of something in the blue-green spectrum - anything between a HSL hue value of 120 and 240.
You then hit a button depending on whether you’d call it blue or green if you were forced to say. The screen refreshes to another place on the same spectrum and you keep making the same blue vs green decision until it narrows down to something approximating what must be the boundary between what you consider to be blue and what you would say is green.
Apparently for me it’s somewhere around hue 175.
This means that for me to call something blue it has to be “more blue” than it would be for 59% of the folk who took the test. So if forced to say whether turquoise was blue or green I apparently be more likely than most to pick green.
My monitor isn’t the best and, as the site notes, that sort of thing is one of many factors that are bound affect the results - so it’s very much “for entertainment purposes only”.
On a similar subject, here’s a handy site that converts from hue values to CSS-style hex colour values.