Among things equally bright, that will appear the most Dim, which is seen on the whitest Ground; and that, on the contrary, will appear the most vivid, whose Ground is the most obscure. Carnation will appear pale upon a Red Ground, but a bright and vivid Red, upon a Yellow one: In like manner, all other Colours may by made to appear different from what they are, by means of the Ground wherewith they are incompass'd.