If we inspect the works of Nature closely, we shall find that they have no uniform tints, whether it be in the animal, vegetal, or mineral creation; - be it flesh or foliage, the earth or the sky, a flower or a stone, - however uniform its colour may appear at a distance, it will, when examined nearly, or even microscopically, be found constituted of a variety of hues and shades, compounded with harmony and intelligence.

Upon the more intimate union, or the blending gradience of contrasts from one to another mutually, depend some of the most fascinating effects of colouring; and the practical principle upon which these are effected is too important to be passed over. This principle consists in the blending and gradating by mixture, while we avoid the compounding of contrasting colours; i.e. the colours must be kept distinct in the act of blending them, or otherwise they will run into dusky neutrality and defile each other, as is the case in blending and gradating from green to red, or from hue to hue - from blue to orange, or to and from coldness and warmth - from yellow to purple, or to and from advancing and retiring colours: it is the same in light and shade, or white and black, which mix with clearness, and compound with hue. Now, there are only two ways in which this distinctness in union of contrasts can be effected in practice: the one of which is by hatching, or breaking them together, in mixture, without compounding them uniformly; and the other is by glazing, in which the colours unite and penetrate mutually, without monotonous composition.

Transparency and opacity constitute another contrast of colouring, the first of which belongs to shade and blackness, the latter to light and whiteness; - even contrast has its contrast, for gradations, or intermedia, are antagonists to contrasts, or extremes; and, upon the right management of contrasts and gradation depends the harmony and melody, the breaks and cadences, the tone, effect, and general expression of a picture; so that painting is an affair of judicious contrasting so far as it regards colour, if even it be not such altogether.

These contrasts may also be variously or totally conjoined; thus, in contrasting any colour, if we wish it to have light or brilliancy, we degrade, or cast its opposite into shade; - if we would have it warm, we cool its antagonist; and if transparent, we oppose it by an opaque contrary, and vice versa, etc.: indeed, in practice, all these must be in some measure combined.

Such are some of the powers of contrast in colouring alone, and such the diversity of art upon which skill in colouring depends. It must not be forgotten, however, that contrasts or extremes, whether of light and shade, or of colours, become violent and offensive when they are not reconciled by the interposition of their media, or a mean which partakes of both extremes of a contrast: thus blue and orange in contrast become reconciled, softened in effect, and harmonised when a broken colour composed of the two is interposed; the same of other colours, shades, and contrasts.

Another important rule which belongs to the consideration of contrasts is, that that which holds of the one species, holds also of the others: hence the maxims of the chiaroscuro are applicable to contrasting colours; each have their focus, should each mutually penetrate and diffuse, - be each repeated subordinately, that is, as principal and secondary, and mutually balance each other, etc. So much, indeed, is the management and mastery of colours dependent on the same principles as light and shade, that it might become a point of good discipline, for the perfect attainment thereof, after acquiring the use of black and white in the chiaroscuro, to paint designs in contrast; that is, with two contrasting colours only, in conjunction with black and white: for example, with blue and orange, previously to attempting the whole together. Black may even be dispensed with in these cases, because it may be compounded, since the neutral grey and third colours always arise from the compounding of contrasting colours, so that even flesh may be painted in this way: for example, with red and green alone, as Gainsborough is said to have done at one period of his practice. It is thus that one part of an art becomes a mirror to the rest.

Some artists have produced pictures in the above hot and cold colours only which have captivated the eye, and are true in theory as regards colour, light, and shade, but generally false in practice with reference to nature, who rarely employs such extreme accordances. Such colouring is, therefore, more beautiful than true. So, indeed, if a painter were to execute a landscape or other subject in the full light of day, as he saw it looking through a prism, so that every object glowed with the hues of the rainbow, such a picture would present a beautiful fairy scene, and be true, as respects colours, but false with regard to nature, and destitute of sentiment. It was this meretricious beauty that obtained for the prism the appellation of "fools' paradise;" and pictures painted with such effects may well merit the same appellation.

By mixing his colours with white, the artist obtains what he has appropriately called his tints; by mixing colours with colours, he obtains compound colours, or hues; finally, by mixing colours or tints with black, he gets what are properly called shades: yet these distinctions are very commonly confounded.

The foregoing classification of colours is an arrangement which exhibits a correct genealogy of their hues and shades in a general view, and enables us to comprehend the simplicity of relation which subsists among an infinity of hues, shades, and tints of colour, while it is calculated to give precision to language respecting colours, the nomenclature of which has ever been exceedingly arbitrary, mutable, and irrelative. The names of colours, consisting of terms imposed without general reference or analogy, according to views and fashions ever varying, are for the most part idiomatical and ambiguous in all languages; yet, boundless as is the variety of hues and compounds, the cultivated eye will readily distinguish the degrees of relation in every possible instance to the preceding denominations of classes.