Earlier quoted context omitted.
...so you are suggesting that one situation where colors match invalidates situations where colors are different. You're implying that if red's meaning in one situation is the same, then red's other meanings in other situations must be the same. Okay I guess. I don't know why you would think that, but I don't have much hope of convincing you otherwise.
If it's all chosen because colors are deeply cultural then they would be the same. If important stuff is all different and arbitrary then it's not cultural.
> all different and arbitrary
Those are the extremes of the spectrum.
Color choices are not at either extreme.
Most color choices are arbitrary, some of them are shallowly cultural, and some of them are deeply cultural.
HN having an orange banner at the top isn't significantly cultural. Traffic lights are worldwide culture. Black or green for positive money and red for negative money are US culture. Red for positive money and black or green for negative money are Chinese culture. These choices tie into older associations, which affects the depth. But even if they were shallow they'd still be culture.