Robert Boyle's Experiments and Consideration Touching Colours, written in 1664 to explain mechanically the so-called quality of colour, contained his various speculations on the nature of colour as well as dozens of experiments which would create change of colours and which seemed to be fitted by his corpuscular explanation. Nevertheless, his colour theory has largely been neglected by historians of science, partly because Newton's revolutionarily modern theory on light and colours overshadowed all his contemporaries' thoughts on colour. This article aims at analysing the structure of Boyle's colour theory in connection with his corpuscular philosophy and experiments. For the first step, with special attention to Descartes, colour theory before Boyle is reviewed. Next, his concept of 'disposition', which he introduced to explain the changes of colour on the basis of his corpuscular philosophy, is analysed. And the limitations of his explanation on the nature of colour, which was closely connected with his 'disposition', is considered. In conclusion, above-mentioned discussions are put together to reveal the internal structure of Boyle's colour theory, corpuscular philosophy and experiments.