Monochrome images
The definition of monochrome is often a question at our competitions…
Monochrome is often considered to be limited to just Black & White. However monochrome can include a B&W image overlaid by any single colour filter, commonly sepia but this can be any other single hue colour.
An image can be tested for monochromaticity by looking at the information panel in Photoshop Elements or similar software while scanning the cursor across the image: in the Info panel, look for the Hue/Saturation/Brightness numbers where the H value will be 0 degrees for B&W or a constant number of degrees for a monochrome image.