This famous group of buildings at 79-107 East Bay Street are excellent examples of 18th & 19th century wharfside mercantile life in Charleston. They were built as individual businesses and residences by prosperous merchants with the ground floors used for commercial use and the upper floors for homes and boarding rooms.
Post Civil War the entire area fell into neglect due to the economics of the time. The wharves along East Bay Street were abandoned and the waterfront silted in, making the area unusable for shipping. The buildings along the Row deteriorated into slum-like conditions by the time of World War I.
In the 1930s Dorothy Porcher Legge renovated her house at 99-101 East Bay Street and came up with the concept of different pastels colors as a homage to the Colonial Caribbean heritage of the Charleston merchants. As the entire Row was renovated and each individual building was painted a pastel … the nickname Rainbow Row came into use to describe the street.
MythBuster: The colors WERE NOT painted on the buildings so illiterate slaves could identify individual businesses!
Also, the main reason these buildings stayed beautiful is because the cost of keeping them up was so much cheaper. They only had to paint one side of the house.