Prior to 1930, when color photography was invented, vintage postcards acquired color in one of two ways: via chromo-lithography or by being hand tinted or hand colored.
Hand Tinted Postcards
The earliest images were of glamorous women, of ladies from exotic countries, of actresses or other early 1900’s celebrities. Later, and especially in France, the theme became a patriotic one with soldiers. After the war the coloring became more strident and less realistic. The image was being decorated for shock value rather than attempting to reproduce real life. The coloring was sometimes crudely done, sometimes very accomplished. Some postcards will feature just small color highlighted areas, others attempt to reproduce a lifelike image. The arrival of color photography and the health issues associated with the hand tinted cards resulted in their demise in the 1930’s.