For those not aware, in most Western countries, the color Blue is associated with right-leaning/conservative political parties, while the color Red is associated with left-leaning/liberal politcal parties. Yet, in the U.S., this is the opposite, with the conservative Republicans being associated with Red and the liberal Democrats being associated with Blue.
What is the historical context for this difference?
While waiting for a thorough reply, you might like "Why are Democrats and Republicans respectively blue and red?" , with replies by /u/ainrialai , and /u/Nimonic mentioning colors in European countries.
This is not to discourage discussion, especially in this case, where I can't find one comprehensive thorough reply.