Who knew these “rainy arches” had such a colorful history?! Source: 17 wonderfully curious facts about rainbows . During the Renaissance, it was decided that, no, there were four colors: red, blue, green, and yellow. By the 17th century, western thinkers had agreed upon five colors: red, yellow, green, blue, and purple. 9. In 1637Continue reading “Facts about Rainbows”