Tuesday, 25 January 2011

I Can Never Mix the Colours I Want

In a bid to recreate the luscious greens of foliage, the artist may reach for any blue and green pigment and blend them together, but murky brown materialises. Hopes for a vibrant purple, as seen on grapes could be quashed when a blend of blue and red yields a dingy grey. In other cases, the colour is too garish, too dark or too wishy-washy or just doesn’t hit the mark. How can the artist mix any colour required for subject matter in painting?

Colour Theory in Art

The Language of Colour Explained
Rachel Shirley
If asked what the primary colours are, the automatic reply might be red, yellow and blue. However many artist pigments containing these labels contain other pigments. Lemon yellow, for instance, has a greenish cast. Cadmium red contains a lot of yellow. Ultramarine blue contains a lot of violet. Since Ultramarine is biased towards red, it would not be a fitting blue counterpart if a piercing green mixture was the objective.

The true definition of a primary colour is one that cannot be made by the mixture of two other colours. By this definition, magenta, yellow and cyan, as found in printing ink, is the most fitting answer, although no pigment can truly match the purity of filtered white light.

The Best Colours for the Artist’s Palette

Despite this, pigments closely approximating this purity exist on the market and which will produce clean secondary colours. Paint manufacturers use varying labels to denote these primary colours. Some may refer to them as “process” or “Winsor” colours. Gleaning colour charts and making comparisons with the primaries of printing ink is how I chose my primary pigments.

Cadmium yellow (pale) is a vivid yellow and is pretty close to the primary yellow of printing ink. Pthalo blue, like cyan, is a sharp blue, although is deeper in tone. Red is not in fact a primary colour, but a secondary colour for it can be achieved by mixing magenta with yellow. Magenta for this reason is a primary colour of an intense rose hue. In terms of oil pigment, resembles permanent rose, which will produce clean violets and indigoes.

Cadmiun yellow (pale), pthalo blue and permanent rose will enable the artist to mix just about any colour needed for painting. More accurate colour judgments can be achieved by examining three factors of the subject matter
  • The colour temperature,
  • The degree of the colour
  • And the tonal value of the colour.
My Youtube clip explaining why red is not a primary colour offering solutions in colour mixing.

Colour Temperature in Painting

As well as the hue, observe the colour temperature of the object, as red can be warm or cool, as can blue. The warm blues found on a summer sky can be achieved by using ultramarine and white, or introducing a little cadmium red or burnt sienna into the blue mix. Cool blues, as seen in lake reflections can be achieved by introducing pthalo blue and a little burnt umber into the mix.

Degrees of a Colour

Of course, few objects are simply “red” or “purple”, but degrees of a hue. This involves toning down the colour with earth colours and neutrals. The subdued blues of distant mountains can be achieved by toning down blue with burnt sienna. Dusty pinks as seen on pansies can be recreated by adding a little burnt sienna, ultramarine and white with the red mix. When it comes to neutral pigments, many are not required. Burnt sienna and burnt umber are the only earth colours I include in my palette, as too many can often result in dirty and lifeless colour mixes.

Tonal Values of Colour

Colours can get in the way of what is light and dark. This interference can cause tones to be overlooked. To filter through this chromatic interference, half-close the eyes. This will break the setting down into areas of light, dark and mid-tones.

Rather than use black or dark grey to darken a colour, try mixing opposing colours, also known as the “complimentary colours.” The complimentary colour to a given colour can be found on the opposing segment on the colour wheel. The complimentary colour of magenta (not red), for instance is green; the complimentary colour of violet is yellow. Introducing a colour’s complimentary to a given colour will produce rich darks rather than dingy blacks.

An evergreen houseplant that harbours lots of shadows can be darkened with any colour on the opposing segment to green. In terms of pigment, this can be permanent rose, cadmium red or burnt sienna, depending upon the intensity and the colour temperature of the darks. Similarly, the shaded areas of a banana can be achieved by adding violet or any colour containing violet, (perhaps ultramarine, or a blend of pthalo blue and permanent rose) to yellow.

Accurate Colour Mixing for Painting

With the above in mind, the artist can recreate any colour with reasonable accuracy, but the real key is to observe the objects in front. Look for slight colour shifts in temperature, intensity and tone. Try out the colour mix on a scrap piece of card before applying it onto canvas. Lastly, look out for colour relationships. How does one colour of an object compare to another? Is it paler, softer, cooler, deeper? Keying in each area of colour with another in a still life will help the painting make sense.

Relevant Articles on Colour Mixing

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