For a fun experiment, try Google finance with the Japanese language tag (https://www.google.com/finance/?hl=ja). Even knowing about the switched colors, it still fools my eyes. Goes to show how deeply ingrained the usual red/green assignment is!
As a (younger) politics junkie I was shocked even though it makes total sense and I've always kinda felt they should've been switched.
“Red” had a very long established political meaning before the new one for “Republican” was adopted, visible in phrases like “better dead than Red”.
“Blue” didn’t, though.
Whew, what a ride for a non-American to figure out what any of these idioms are supposed to mean.
Annoyingly my home country (Germany) uses both black and blue to indicate conservative or right-wing parties. Conservatives being indicated in blue seems to be somewhat common internationally but black is historically tied to anarchism (which uses a black flag to be the flag of all people that no one country can claim, unlike the white flag of surrender).
Every party has an official color of course, but they're not always used in reporting. For example, while the CSU uses blue for its logo, the CDU uses red but still is traditionally represented in black.
The GOP being “red” and Democrats being “blue” were not colors chosen by the parties. In the seventies, Television broadcasters started using colors to identify voting trends and soon enough they all settled on those particular colors for the parties. There may have been some attempt to not use red for Democrats to avoid reinforcing the “lefty” stereotype.
Not to the UK however. In the British Parliament seating is based on governing party (right side of the Speaker (Commons) or right side of the Throne (House of Lords) and the opposition on the other side)
However for example in Germany there was a relatively big debate earlier in this legislative period, when the liberal party (FDP) wanted to move to the center, switching seats with the conservatives (CDU/CSU) to move away from the far right party (AfD) The "traditional" left-right spectrum was a key argument in the debate.
The problem with the Democrats and the Republicans isn't that they're two coherent parties. They're both parent organizations for state-level parties which can be politically extremely different from each other. And those parties can themselves be ideologically incoherent because people join them simply because there is no point in joining a third party instead, not to mention that in some cases in-party election (e.g. the primaries) allow non-members to vote, which further messes with their political coherence. And don't even get me started on how PACs and big donors affect campaigning.
Is this just a historical path-dependent thing — e.g. stock-exchange trading floors traditionally all buying their sign boards from some specialty company that produced boards specialized to have exactly two "color channels" — red and green — and then, when the TSE got theirs, it was all they could do to just wire the color channels up backwards?
(I guess there are a few types of meters that always use red as high and green as low — e.g. pressure gauges. But that's because red in those cases means danger. A high stock value isn't dangerous!)
- Homer Simpson on stocks