COLOURTHE COLOUR WHEELHUE: A pure hue is an undiluted colour, with no addition of white, grey or black. Three hues are primary colours: red, yellow and blue.Three other hues, each resulting from mixing two primary colours, are secondary colours: violet (red + blue), green (yellow + blue) and orange (yellow + red).

VALUE: Each pure hue can become lighter or darker. These graduations are called values. Adding white to a hue produces the lighter values referred to as tints; the addition of black results in darker shades.

SATURATION: Hues can be bright or dull, a condition described as degree of saturation (also called intensity). Differences in saturation result from the amount of grey added to a hue; the more grey you add, the duller and less saturated the colour. Grey values are called tones.

WARM VERSUS COOL COLOURS: When you draw a line across the colour wheel between green and yellow-green on one side, between red and red-violet on the other, you divide the colours into two groups; one warm, the other cool. The warm colours are yellow, orange and red; the cool ones are violet, blue and green.

COLOUR COMBINATIONS: The colour wheel enables you to view all sorts of colour combinations at a glance. Three possible schemes are monochromatic, harmonious and contrasting (also called complementary). Also discussed are white and grey, two “colours” not represented on the wheel but widely found in flowers and foliage. Both can be used in virtually any colour combination.

MONOCHROMATIC: The simplest colour scheme is centred on a single hue – blue, for example – and includes flowers in all that hue’s tints, shades, and various saturations. The result is almost automatically pleasant, though monochromatic schemes based on warm colours run the risk of being overassertive. To avoid monotony, select plants with different forms and a variety of foliage colours, textures and shapes.

HARMONIOUS: On the colour wheel, harmonious colours are those that lie between any two primary hues. Moving from yellow to red, for example, you’ll find yellow-orange, orange, and orange-red. A broadly harmonious composition includes the full range of colours between the two primaries as well as one of those two hues; the most limited harmonious scheme encompasses just two adjacent colours on the wheel (yellow and yellow-orange, for example). Thanks to the close relationship between the colours used, harmonious combinations are pleasing to the eye. And because two hues are involved rather than just one, they’re a bit livelier than monochromatic schemes.

CONTRASTING: Colour contrasts occur between two totally unrelated colours. The primary hues provide an obvious example of vivid contrasts. Another contrast is formed by complementary colours – those opposite each other on the colour wheel, such as blue and orange or yellow and violet. In most cases, you’ll be aiming for contrasting flower colours; but note that the complement to red is green. Vivid red scarlet sage (Salvia splendens) against a backdrop of green foliage creates as true a contrast as blue delphiniums behind orange daylilies (Hemerocallis).

Contrasts involving fully saturated colours are most effective when used in moderation, as accents or foils for quieter, more harmonious schemes. Used in large quantity, these vivid contrasts both jar the eye and lose their impact. Also keep in mind that contrasting colours are typically more effective if used in unequal amounts; rather than composing a planting bed of half yellow iris and half violet ones, use one colour sparingly, as an accent to greater amounts of the other.Contrasting colours need not be bright. For a softer look, use tints: cream and lavender, for example, instead of yellow and violet. You can also mix values when you create contrast, combining a fully saturated colour with a softer, paler one – intense blue with pale peach, for instance, or bright green foliage as a foil for soft pink flowers.

WHITE: Gardeners think of white as a colour, but to colour theorists, its atonal – the complete lack of colour. As white is added to a colour, it produces lighter and lighter tints. White then, can assort with all colours, light or dark. Combined with lighter values, it is harmonious; its lack of colour seems closely related to the paleness around it. Used with fully saturated colours or darker shades, it offers a sharp contrast. (Use it sparingly in this role – overuse of contrast will give the planting a discordant, uneasy feel.)

GREY: Though you won’t find truly grey flowers, there are plenty of grey-leafed plants. Usually thought of as cool colour, grey actually results from mixing any two complementary colours.This explains its unique ability to fit into virtually any scheme, warm or cool. Grey is the great moderator: its soft neutrality tones down brilliance, highlights every colour, and imparts softness to the overall picture.

PRIMARY COLOURS SHADE- HUE-TINT-TONE

COMPLEMENTARY (CONTRASTING) ANALOGOUS or HARMONIOUS

CHOOSING COLOUR: It’s much easier to pick one plant that you like than to choose many that work well together. If you’re in doubt about mixing colours, try one of the following simple themes.

Cool colours blue, purple, rose, pink and white – create a quiet, restful mood. Warm colours red, orange, and yellow – stimulate the eye and produce a sense of

excitement. Contrasting colours add interest to the cool colours and tone down the warm colours.

Yellow brightens a blue and purple garden, whereas blue calms a bed of red or orange flowers.

One colour, in many shades, is always more interesting than a solid band of flat colour. White complements other colours, and helps unify mixed colours.

White, grey & silver create a sense of space, coolness and serenity. Do not plant the whole garden this way but use them in an area which is not immediately apparent, so that on turning a corner, a display of relaxing colours comes as a surprise.

Green foliage plants harmonise with white and silver plants. Reds are the most dominant of all colours when seen against a mid-green

background. Densely red flowers such as poppies, have a three dimensional effect and appear to stand out from the foliage and stems. Most reds however appear as shades.

Gold & yellow are the brightest colours in a garden and can overpower and subdue demure and light colours, therefore use carefully. Soft yellows however, happily blend with white, silver and grey. But ensure that the total area given to yellow is less than that allocated to the white.

Blue & purple range from soft and gentle blue to strong and dominant purple. Shades at the pastel end of this range blend with less dominant shades of yellow. Do not try to blend dominant reds, purple and yellows.