Why do some colours clash?

[analog_sa]

In a previous job we had meetings that lasted hours about white.

More and more jobs like this in the future. Usually DEI related 😎

 

[myleftear]

We once made a little experimental installation: 2 identical mockups (scale 1:6) of a room: wooden floor, white walls (ncs 0500), a model chair, and a pink piece of cardboard on the floor. A spotlight pointed down onto that card, creating a pink reflection.
The walls that were painted with natural pigments (chalk, marble-dust etc) had the reflection about twice as high up the wall as the walls that were painted with a casual, but high quality industrial paint…

 

[JMFahey]

. And it's constantly changing with the sun and weather and internal lights.
To agonize over tiny differences in white paint chips seems to literally be missing the big picture.

You have a point there.

White is not "white" but "the surface which reflects all colours the same".
Since our eyes only get the reflected light we can only judge whiteness by it.
Possibilities of error or at least misjudgements are always there