It’s logical that white should symbolize purity and innocence and that black should mean fear or mystery. Since blood is red, and so are blushing faces, Using red as a sign of danger, anger or passion makes sense. Green is the color of leaves on plants and trees, so that color logically represents fertility, etc. Purple represents royalty because, centuries ago, purple dye was very expensive and only rich people could afford it. But why does blue, the color of beautiful skies and seas represent sadness? To me, blue is the happiest color. Does anyone know where, and why, the idea that blue is a sad color originated?