tints, colours, shades

This is called value, the ability to create shades and tints for a 3 dimensional feeling. Shades are created by adding black to a colour, while tints are created by adding white to a colour.

Tints are made by adding white. In other words, add varying amounts of white to your base color to make tints of it. Likewise, add black to your base color to make shades.

Spectrum

Monochromatic refers to the use of a single color in a variety of tints and shades.