Typography Is Impossible
Marcin Wichary (2016):
Sticking out is not unusual in typography, even if you don’t use flamboyant typefaces like Zapfino. Here are four examples from Medium today where cropping text precisely at its box’s edges would cut stuff off[…] The box is just a suggestion.
[…]
So, yes: two fonts of the same size are likely to not actually be the same size.
There are consequences of this beyond just font sizing. Since the font designer can do whatever they want within the box, some fonts will inevitably end up closer to top, or to bottom. You might have to take that into account when laying things out[…]
[…]
Type is aligned when it feels aligned, not when it actually is aligned.
Color management is similar. Not that there isn't a lot of physics and physiology etc. But boy is there a lot more!
For example: almost all "white" paper is actually blue-ish. Both because blue-ish just looks whiter, and also because they use optical whiteners that work with the UV components of light so the paper actually emits more than 100% of the visible light hitting it.
If you try to *accurately* match colors relative to that white-point, everything will look very yellow to a human observer, despite the fact that your photospectrometer will tell you that you hit the color very precisely, because the human visual system interprets the brightest large-is and roughly neutral color it sees as "white". And so yes, the color you can see can depend on things outside the object you're color matching.
And then there are psycho-social effects, so for example as humans we are much more sensitive to mismatches in skin-tone, so when you need to adjust everything to keep relative color distances roughly the same you might need to distort the mapping around the skin-tone area.
Fun times!