In other countries there may be confusion when contemporary stands for modern colouring as opposed to old or original colour. To avoid misunuderstanding, it is best to ask and make sure. Later application of colour to a map originally printed in black and white or monochrome, does not make it a fake. However, it is relatively easy to pass off skilled modern colouring, or widespread retouching of an earlier coloured map as original colouring. This would be improper.
Original colouring is sometimes sloppy, as it was occasionally done by children.
Old colours may have soaked into the paper, especially green colour, whereas in general modern colours do not. The size of the printed surface, and on occasion the size of the plate, is known for most early maps, and can be found in reference books. The size of the original paper sheets is simetimes known, but more difficult to verify. Margins may have been trimmed or replaced, using old paper, but not to the original sheet size. This will be discernible using a magnifying glass.