Monochrome definition (PSA)
An image is considered to be Monochrome only if it gives the impression of having no color (i.e. contains only shades of grey which can include pure black and pure white) OR it gives the impression of being a greyscale image that has been toned in one color across the entire image. (For example by Sepia, red, gold, etc.) A greyscale or multi-colored image modified or giving the impression of having been modified by partial toning, multi-toning or by the inclusion of spot coloring does not meet the definition of monochrome and shall be classified as a Color Work.
Monochrome definition (FIAP)
A black and white work fitting from the very dark grey (black) to the very clear grey (white) is a monochrome work with the various shades of grey. A black and white work toned entirely in a single colour will remain a monochrome work able to stand in the black and white category; such a work can be reproduced in black and white in the catalogue of a salon under FIAP Patronage.
On the other hand a black and white work modified by a partial toning or by the addition of one colour becomes a colour work (polychrome) to stand in the colour category; such a work requires colour reproduction in the catalogue of a salon under FIAP Patronage