Christian flag, while there is no one official flag of all Christian churches, by common usage a so-called Christian flag has come to be recognized by a number of them. It consists of a white rectangular field with a blue rectangle in the upper corner at the mast side which contains a red Latin cross. Charles C. Overton, a New York Sunday school superintendent, has been credited with designing this flag in 1887. Overton selected white to signify purity; blue, courage; and the red cross, sacrifice. Other designs incorporating the cross have been officially adopted by various churches.