Although the woodcut illustrations of early printed books were occasionally printed in color -- Erhard Ratdolt was an early pioneer, issuing woodcuts in up to five colors -- it was much more usual for illustrations to be printed in black alone. But color could easily be added after the fact, as these three examples show. All three are from books printed by the German goldsmith-turned-printer Anton Koberger:
1) Neunte Deutsche Bibel, Nuremberg, 1483
2) Schatzbehalter, Nuremberg, 1491
3) Weltchronik, Nuremberg, 1493 [The Nuremberg Chronicle]
Koberger was one of the most successful German printers of the incunable period -- the period from the development of printing with movable type in the middle of the 15th century to the end of the year 1500.
Wilhelm Ludwig Schreiber. Der Buchholzschnitt im 15. Jahrhundert in Original-Beispielen. Munich: Weiss, 1929. Special Collections Rare Vault Folio NE905 .S2