In nature blue is used as a softer color. Red on the other had is used mostly as highlighting. Blue is used as a main color like the sky and water. If the sky were red, it would hurt your eyes, and I do not think as many people would just gaze up into it. The sky was designed to be "background" and not take center position when you look outside.
In human emotions red generally stands for hotheaded. Blue usually tends to mean cooler or cold. When someone "sees red" they are very angry or upset. However, when someone is feeling blue they are upset, melancholy, or depressed.
The color of ones skin also follows this pattern. When one's skin becomes red it means they are too hot or have recently been burned. While on the other hand, blue skin means the person is cold or has been exposed to the cold for an extended period.
When buying products, red is generally considered "flashy." Most people do not buy a brand-new sports car, and then get it painted blue. The color they want is cherry red because it stands out and shouts, "Look at me." The same goes with clothes. Blue jeans are considered casual and normal, but if someone wears red jeans, watch out.
So, in the scheme of colors, blue is considered a softer, a gentler, and a cooler color. Red is used to emphasize something or draw attention. It is a hotter brighter color, that when used correctly is great, but blue is the cooler color.