January 5, 2021
For the next few weeks we’ll be looking at primary colours used on their own and their use with each of their complementary colours. Primary colours will also be used with closely related hues to make harmonious compositions.
We’ll also explore some of the effects of colours on each other, after all colour can seriously affect your eyes or at the least deceive them a little!
Look at the appearance of the four blue squares on the right and middle columns above. Do they look different? What happens at their edges?
Then: stare at each of the squares in turn for about a minute then look at the blank space below before going on to the next one. What do you see?
For even more spectacular after images stare at the colour wheel below and then at a white space. these after images and illusions are with us all the time we are seeing.
To start with, here are a few basic definitions that are relevant to the course.: please skip if you are already up to speed with this!
Hue: a pure colour of a certain wavelength in the visible light spectrum.
Colour wheel; this should be a circle with a continuum of all the different hues in the visible spectrum. In practical terms this has been reduced to a beach ball of just six colours which represent six major groups of colour as used for painting; firstly, the three primary colours; red, yellow, and blue called primaries because they cannot be mixed from other colours; secondly, the three secondary colours orange, green and purple which can be mixed from the primary colours and which lie in between the colours they are mixed from on the colour wheel. Scientists and artists have invented a huge number of colour wheels, some of which include many more colours and also tints and shades at different levels within the circle.
Analogous colours; colours close in hue and next to each other on the colour wheel. the colour wheel. e.g. red and a reddish purple
Saturation : the purity of the colour, which is occasionally and I think confusingly, called intensity. To de-saturate a colour mix the pure hue (fully saturated colour), with its complementary colour, or black or white. The saturation of some colours is altered radically by even the smallest amounts of these; for example yellow is very rapidly changed by the addition of the smallest amounts of purple or black.
Tone: how light or dark a colour appears. Every pure hue has an intrinsic tone. A pure yellow for instance is always paler than a pure red. The additionof black, both de-saturates a hue and lowers or darkens its tone. Colours darkened in this way are usually called shades. The addition of a complementary colour also lowers its tone.
The addition of white to a hue lightens it and is said to raise its tone to make tints.
The definition of tints and shades is not always consistent as pastels are often labelled as e.g. tints 1 to 6 where usually a stick labelled tint 1 or 0 is the palest and is the pure colour plus white, and a stick labelled tint 6 is the darkest of that colour made up of the pure hue plus black.
This week’s colour is blue. Often the colour of melancholy and depression as in Picasso’s blue period portraits, I didn’t choose blue first because of Covid creating so much depression this New Year. No, I chose it first because it’s also the colour of sunny skies and Mediterranean waters, and because as you will see next week blue is great to combine with its complementary orange.
The blue pigments I have used for the exercises are
French Ultramarine (warm),
Cobalt Blue (warm)
Phthalo Blue, green shade or Prussian blue (cold)
It’s useful to have at least one warm and one cool blue to work with. If I had only two I would probably favour Ultramarine and Cerulean, but the richness of cobalt and the dark tones that can be produced with Phthalo or Prussian Blues are very useful additions.
For this week you will also need a black and white, and perhaps a couple of analogous colours a blueish purple and a blueish green or turquoise.
Used at full strength pure cobalt and pure cerulean are not as dark in tone as Ultramarine or Phthalo Blue and the darkest is Prussian blue. Phthalo Blue, Prussian blue and Ultramarine are generally more transparent than Cerulean and cobalt blue.
What does this mean in practice?
Transparency only applies to watercolour, oil and acrylic paints as if you are using gouache or pastel you are effectively working with an inherently opaque medium. Transparent colours deepen the more layers of colour that are added. Opaque colours laid down at full strength do not become darker when further layers are added. Very often it is difficult unless you know their position to identify the transparent colours of watercolour pans in a box because they all appear so dark whereas the more opaque colours give away their identity on sight; e.g, cadmium red, cadmium orange etc.
Exercises; I have chosen watercolour for this week but most could be done with pastel, acrylic or gouache. I hope to provide some pastel examples later in the week. The illustrations are only to give you ideas of ways to explore the blue pigments in your own boxes,
1. Tone and saturation
Take a blue pigment and try 1. diluting with water, 2. mixing with increasing amounts of white, 3. mixing with black and adding increasing amounts of white, and 4. compare with black to which increasing amounts of white are added.
Try this for a warm blue like Ultramarine and a cool blue like Cerulean or Phthalo Blue. Adding water or white will make tints and adding black will darken the colour and de-saturate the blue. Adding white to this mix will produce blueish greys.
2. Optical properties
Dark and light surrounds, disappearing boundaries; very closely related hues of the same tone.
Make a study where similar shapes of one hue are surrounded by white, a much darker hue or by a closely related hue of the same tone. An example is given below.
You may choose to do 3 or 4 below;
3. Make a painting/study using just blue pigments
4. Make a painting or study using blue pigments, and black. You may also use white and a couple of analogous colours like a blueish green and/or a blueish purple. The general effect should be that you are making a predominantly blue and harmonious painting.
3 and 4 may be your own composition or your version of a famous painting where the predominant colour is blue.
What conditions make a blue advance, float, or recede?
With regard to tone and hue how does a background colour affect how a blue hue appears?
Pinterest board for reference.
The link for this week’s board is:
which includes abstract works by Patrick Heron, Marc Rothko, Josef Albers, Kandinsky and Matisse alongside works from Picasso’s blue period.
Starting with Pastel
Wednesdays 14th April to 5th May