text: " "Though it is not my _business_ to enter into the detail of our art yet I must take this opportunity of mentioning one of the means of producing that great effect which we observe in the works of the Venetian painters as I think it is not generally known or observed that the masses of light in a picture be always of a warm mellow colour yellow red or yellowish white; and that the blue the grey or the green colours be kept almost entirely out of these masses and be used only to support and set off these warm colours; and for this purpose a small proportion of cold colours will be sufficient