What is generally produced by adding grey to a primary colour?

Correct answer: Tone

The governing concept is the difference between tint, shade and tone. Adding grey to a primary colour generally produces a tone, making the colour appear less intense, softer and more muted. Adding white creates a tint, which raises lightness, whereas adding black creates a shade, which lowers value. The mixture does not become a secondary colour because secondary colours are formed by combining two primary colours, so option A is correct.