Differentiate among a color display, gray scale display, and a black-and-white display

Black and white:

It has only two values namely black or white. The white colour in the image will be represented as “white” and other colour part will be displayed as black.

Grey-scale:

Again the white part does not have a change, the black and other coloured items will be displayed in grey.

Coloured image:

It would display the actual colour of the image. The number of colours and shades depends on the original image from where actually it has been shooted and it also depends on the quality of the camera.