Human Nature, Ch. VIII, § 2, circa médium

4. Also the pleasures of the eye consist in a certain equality of colour ; for light, the most glorious of ail colours is made by equal opération of the object ; whereas colour is perturbed, that is to say, unequal light, as hath been said, chapter II, section 8. (Human Nature, Ch. VIII, § 2, circa finem ).