Chap. CCXXVII.—Of the Colours produced by the Mixture of other Colours, called secondary Colours.
The first of all simple colours is White, though philosophers will not acknowledge either White or Black to be colours; because the first is the cause, or the receiver of colours, the other totally deprived of them. But as painters cannot do without either, we shall place them among the others; and according to this order of things, White will be the first, Yellow the second, Green the third, Blue the fourth, Red the fifth, and Black the sixth. We shall set down White for the representative of light, without which no colour can be seen; Yellow for the earth; Green for water; Blue for air; Red for fire; and Black for total darkness.
If you wish to see by a short process the variety of all the mixed, or composed colours, take some coloured glasses, and, through them, look at all the country round: you will find that the colour of each object will be altered and mixed with the colour of the glass through which it is seen; observe which colour is made better, and which is hurt by the mixture. If the glass be yellow, the colour of the objects may either be improved, or greatly impaired by it. Black and White will be most altered, while Green and Yellow will be meliorated. In the same manner you may go through all the mixtures of colours, which are infinite. Select those which are new and agreeable to the sight; and following the same method you may go on with two glasses, or three, till you have found what will best answer your purpose.