Which colour should be used in greater quantity to create light grey?

Correct answer: White

Light grey is produced by using a larger amount of white and adding only a small amount of black. White raises the value or lightness of the mixture, while black lowers it; therefore option A is correct. If black is used in greater quantity, the result becomes dark grey. Red or blue would introduce a chromatic hue rather than a neutral grey. The exact shade can be adjusted by adding black gradually to white and testing the mixture.