§ 55 V. VI. CONTRASTS, QUANTITY, TONE. 99 



come under the first class as positive contrasts ; and the 

 greatest and most violent contrast is between those two 

 colours. Nor do all other accidental colours contrast with 

 each other in an equal degree, or under the same conditions ; 

 and I cannot too often repeat that, because blue and orange 

 are most harmonious contrasts, it does not follow that red 

 and blue-green should be so, and still less green and reddish- 

 violet, which are a most obvious and disagreeable discord. 

 (See above, p. 74.) 



VI. It is of great importance to understand the effect 

 which colours have on each other when in juxtaposition; and 

 allowance must be made for this in their arrangement. For 

 as black when next to white appears blacker, and the white 

 next to black looks brighter, so many colours heighten each 

 other's effect; while others diminish it (p. 62). The action of 

 yellow on some others has been noticed in p. 76. Any colour 

 may be increased or decreased in intensity, according to the 

 greater or less contrast it receives from a neighbour. Its 

 power too may be altered by a disproportionate quantity of 

 another, and also by juxtaposition with the same quantity of 

 another of a fuller tone, or more powerful than itself. And 

 this is the case when colours are of the same as when they 

 are of different hues. It seldom happens that the union of 

 two different colours, in very different quantities, has a good 

 effect. There are, however, some remarkable exceptions to this, 

 as in the ease of red and white, and some others which I shall 

 have occasion to mention (Sect. XVIII.) ; and there are also 

 some occasions where colours of a deep and a light tone may 

 be employed together to advantage ; particularly when many 

 are combined to form a design. As a general rule for colours 

 to agree, the essential point is, that they be of the same 

 intensity of tone; for two which agree admirably when both 

 are of the same power, lose their proper effect the moment 

 the equilibrium ceases to be maintained ; as when a deep tone 



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