The general concept of predicting the colour sensitivity to random colorant concentration errors and the colour correctability of a colour matching recipe are reviewed and generalised in this paper. The treatment of both quantities is unified either in the concentration space or, equivalently, in colour space. The concept of the recipe's colour balance is revised. Oulton's concept of recipe colour sensitivity to proportional concentration errors is also briefly reviewed and extended to obtain another measure of recipe sensitivity to random concentration errors. The differences and connections among the two measures of recipe sensitivity to random errors and Oulton's measure of recipe sensitivity to proportional errors are discussed and illustrated by numerical examples. Estimates of maximal colour error, caused by given maximal weighing and strength errors, are developed.