Neurologic coherence between numbers and colors?
In some sense yes, we all have some mild synesthesia and tend to associate some shapes with some colors/names etc. There is a famous experiment from Ramachandran showing that when asked to identify 2 shapes, one called "bouba" and the other one "kiki", almost everybody reports the rounder shape as "bouba" and the sharper one as "kiki". It's unclear why, it's a classical chicken or egg problem. It could suggest that language reflects to some extent the visual appearance of objects. Or that from experience we match the visual appearance of objects with sounds they are (randomly) often associated with. In any case, if one takes the time to conduct polls and measure how often a stimulus is associated with another stimulus one can, at least in some situations, predict to a fairly large degree what people will think.



https://en.wikipedia.org/wiki/Bouba/kiki_effect