All distances should have their outlines confused and unfinished, while foreground objects should be bold and determined.
Objects appear most remote that are divested of their outline, as in Turner's pictures—giving the idea of space and largeness.
Of the beauty of reflexes, Da Vinci says: 'If you mean the proximity of one colour should give beauty to another that terminates near it, observe the rays of the sun in the composition of the rainbow, the colours of which are generated by the falling rain, when each drop in its descent takes every colour of the bow.'
Displaying the various colours that compose either the light or the shade, or lights and darks, that are to stand as such, into large and subtly interwoven portions,—the blending and the opposition of hot and cold colours, and of light with dark, together with strict attention to their strength and relations (for the most discordant and opposite properties will produce harmony, under certain circumstances and arrangement), so that the masses of light and shade, and the breadth of the whole, are not disturbed,—are the leading circumstances that should engage the anxious attention.
HARMONY AND CONTRAST.
Harmony, as in Nature, is the agreeable accordance of the various colours that form the parts of a scene into a whole; divested, in their dispersion, of their harshness by the everywhere surrounding atmosphere: this may be tested by holding a piece of silk, the exact colour of the grass at our feet, up against a field, when the field will become grey in comparison.
The exact degree of strength, or of tone, greatly tend to reconcile the harmony of a picture.
Harmony consists more in the power of bringing colours together, than in the mere arrangement of the colours themselves.