Red and Blue

[EdwardTking]

Why are the colors red and blue often used as opposing colors? Why so few red vs green, or blue vs. orange?; colors which are opposite on the color wheel.

For example:
Red states vs. Blue States.
Coca Cola vs. Pepsi
Office Depot shirts vs. Office Max shirts.

It is complicated, buthistorically Red, Blue and Yellow
were considered the three primary colours.
(Actually it is Cyan, Magenta and another.)

And primary colours were considered superior to
derived colours such as orange (red and yellow)
and green (yellow and blue).

Now yellow is quite light (yellow banners and uniforms
would get dirty very quick; so people peferred red or blue.)

Red via Green is less of a contrast; particularly
as many people are partly red-green colour blind.

And rather than orange; people prefered gold colour.

 

[Azadre]

It is complicated, buthistorically Red, Blue and Yellow
were considered the three primary colours.
(Actually it is Cyan, Magenta and another.)

And primary colours were considered superior to
derived colours such as orange (red and yellow)
and green (yellow and blue).

Now yellow is quite light (yellow banners and uniforms
would get dirty very quick; so people peferred red or blue.)

Red via Green is less of a contrast; particularly
as many people are partly red-green colour blind.

And rather than orange; people prefered gold colour.

cyan, magenta, yellow