Part 2, project 3, exercise 1: Colour relationships – simultaneous contrast

Updated on 27 February 2017 (Harvard referencing).

15/16 May 2016. I still had a large part of the neutral grey ground prepared for the last colour experiments, so I used this for my exercise on exploring simultaneous colour contrast, i.e. the effect that colours appear to change relative to the colours they are seen against. Colours, which are close together on the colour wheel, appear more like one colour than when seen separately, while colours opposite to one another on the wheel reinforce each other. In the colours I chose (Fig. 1) the relative strength of this “cancelling out effect” is visible with the colours yellow, and both orange and green, which lie next to yellow on the colour wheel. While, for example, the yellow square inside the yellow-green frame (no. 3) is hardly noticeable as a separate colour, it is relatively clearly visible inside the green (no. 5) or dark orange (no. 2) frame. In producing the squares I had to take care not to leave any of the background colour to shine through at the boundary between each colour pair. The effect on the pair was instantaneous, at least to me. Even in the fourth square from the left, the tiny areas of grey between the yellow and green are so prominent that they shift viewer attention away from the colour relationship I wanted to test. In addition, it was very difficult to take a photo at all that was not either too dark or too bright, but then with shiny brush strokes, all of which have their own influence on the colour relationships explored here.

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Figure 1. Simultaneous contrast in colours close to one another in the colour spectrum

Next I was asked to produce another (yellow) square, this time with its tonally equal complementary colour added, and to observe the effect (Fig. 2). To be honest, I would not know how to describe the influence. On the one hand, violet being the complementary colour to yellow, the combination works to enhance contrast in the pair. At the same time, making the pair tonally equal seems to work in the opposite direction. Colour contrast and tonal contrast appear to work hand in hand, as I would expect when thinking about it, but I may be wrong with my impression. In addition, I am not sure, whether I was completely successful in matching tonal values in the example below. No matter how much white I add, the yellow always seems brighter and there seems to be a limit regarding the potential of adding white in tonal adjustment (see explanation for this effect below).

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Figure 2. Complementary pair of colours, contrast with tonal values made equal

Finally I was asked to produce square frames of a complementary pair and to observe their effect on a neutral grey centre in comparison with a white frame (Fig. 3). Since I was already using a neutral grey ground, I did not understand the instruction of having to paint an additional neutral grey centre, so I omitted that step. In order to see the effects the different frames have on their centres, I need to half close my eyes and carefully cover the squares I do not want to look at, since they are a source of distraction. To me, the grey square appears darkest and similar (but not equal) in the tonally similar complementary pair of yellow and violet, somewhat lighter inside the white and lightest inside the tonally unchanged violet frame which I added out of interest. When looking for information on the internet regarding the relative brightness of colours, it is the yellow-green receptors in the human retina that are the most sensitive (Kaye, 2014). Since the human brain tends to reinforce differences in order to separate information, it is to be expected that the brighter the square, the darker the centre will appear, and vice versa. The strongest colour contrast is produced by combining yellow and black (Perron, n.d.), so my observation regarding the white square is correct. This means, however, that no matter how much white I add to a colour, the tonal value of yellow/green-yellow may in the end be unattainable. This is my own interpretation and again I may be wrong, but it tells me that it is necessary to be very careful with the use and placement of yellow in a painting.

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Figure 3. Complementary pair of colours on neutral grey

I am planning to explore colour contrast for Assignment 2 (separate posts to follow) and will try and keep investigating the subject throughout the preparations.

Resources:

  1. Kaye, T. (2014) What color do humans see as brightest? [online]. Quora. Available at: https://www.quora.com/What-color-do-humans-see-as-brightest [Accessed 16 May 2016]
  2. Perron, C. (n.d.) Colour Choices on Web Pages: Contrast vs Readability [online]. Carin Perron Colour Theory and Practice. Available at: http://www.writer2001.com/colwebcontrast.htm [Accessed 16 May 2016]
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Part 2, project 1, exercises 1 to 3: mixing greys and colours

Updated on 20 February 2017 (Harvard referencing).

12 April 2016. Since the exercises on mixing colours are intimately connected, I waited until I had completed all of them in order to write a summary of the experience, which, as has been noticed by a number of fellow students before, required the input of
enormous amounts of paint and time. In return it gave a growing understanding of the nature of colour and, in the case of some of the experiments, a near-meditative peace of mind.

Exercise 1: Mixing greys – anachromatic scale

Since I had no previous experience whatsoever regarding the proportions of white and black needed in producing a sensible number of steps for the above scale, I started ever so carefully, adding only minute quantities of black each time. This resulted in a relatively impressive 64 shades in total (see Fig. 1 below). At the dark end of the scale the differences are unfortunately very difficult to see in the photo. With my limited knowledge of photo editing I made things not much better, but in nature there is a continuous darkening visible. Interestingly, I went through three cycles of mixing in black and adding to the darker end of the scale before my eyes/brain would agree that NOW there was a real difference to the shades put on before. When, in the end, looking at the result, the scale went smootly from white to black.

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Figure 1. Anachromatic scale using ivory black, 64 steps

Taking two small pieces of paper with neutral grey and placing them on both ends of the scale as advised in the study guide, revealed that the same tone looks darker near white than near black (Fig. 2a and 2 b below). According to Chevreul’s idea that the brain tends to exaggerate differences in tone in order to allow a clear differentiation – see my previous post on Chevreul’s colour theory (Lacher-Bryk, 2016). I assume that probably the real differences may be less prominent on both ends of the scale.


The neutral grey produced in the above exercise I then used to prepare an A2-sized ground on acrylic paper. Despite having assumed that I had mixed my grey very thoroughly I noticed differences in tone across the ground. So I made a mental note that it would be necessary to work extremely thoroughly with totally clean tools to achieve acceptable results during the exercises to follow.
It took me two whole days to complete the experiments below and left me with literally kilograms of little heaps of mixed paint. Since I have no use for them in the near future it will mean having to discard them with mixed feelings. So I took a souvenir photo of the lot (Fig. 3):

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Figure 3. Leftover colour mixes

The following photo shows an overview of the colour mixing exercises (Fig. 4):

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Figure 4. Results of the colour mixing exercises


Exercise 2: Primary and secondary colour mixing

To be honest, I am the owner of only a few hues of acrylic paint. I like mixing and I have accumulated some intuitive experience in decades of watercolour painting. Of course, there are some important differences when mixing acrylic paint when compared to watercolour, in particular the source of white mainly as paper white in the one case, and white pigment in the other.
So here is my modest selection of primary colours (Fig. 5):

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Figure 5. My primary colours

In the case where I had only two hues of a colour (yellow and red) swapping their positions had no effect regarding the perceived relative tone, but in my opinion it does make a difference to the story told by the hues, tiny as it may be, when reading from light to dark or vice versa. With the blues, however, the primary blue (cyan) looks lighter when placed between two darker colours (ultramarine and bluegreen in my case) than when it sits to the side of the darker hues. The most intense hues of the above were primary red, Naphthol red deep and primary blue (cyan), so I used these in the following mixing experiments (Fig. 6):

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Figure 6. Primary colour mixing: top – yellow to red, middle – yellow to blue, bottom – red to blue

The first thing I noticed when comparing the three sets of scales was that identical handling does not produce scales of equal length. While the change from yellow to red was achieved comparatively quickly and the mixes on the red side of the scale look relatively similar (not only on the photo but also in reality), the change from yellow to blue produced an enormous variety of clearly different greenish hues. I even ran out of paper at the end of the scale and had to stop it more abruptly than intended. The mix between red and blue produced did produce some of the murky dark mix mentioned in the study guide, although I would rate some of the hues towards the blue end of the scale as something like violet.
Still, testing other combinations of blue and red in order to make more believable violets gave the following results (Fig. 7). The photo, unfortunately, does not faithfully reproduce the hues especially in the top row, but the most convincing results came from primary magenta mixed with primary blue (bottom row).

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Figure 7. Mixing violets: top – Naphthol red deep and ultramarine, middle – primary magenta and ultramarine, bottom – primary magenta and primary blue

The most time and paint-demanding experiments of this exercise were those aimed at mixing secondary colours in the above manner but trying to keep tonal values constant. I continued mixing in the second colour plus white until the hue of the white+colour mix was the same as the original second pigment. A whole day was devoted to the following three scales (Fig. 8):

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Figure 8. Mixing secondary colours while keeping tonal values constant: top – yellow to red, middle: yellow to blue, bottom: red to blue

The first thing to mention here is that I may have misinterpreted the instructions. I don’t know whether I may have been required to mix in some white with the starting primary colour, too. I did not and in the case of yellow as starting colour this meant that I had to add ten times the amount of white, and sometimes far more, with each tiny blob of secondary colour in order to keep tonal values constant. This also meant discarding enormous amount of paint each time I started another hue. Interestingly, the same effect was not noticeable after two thirds of the red to blue scale. There were 12 steps in the scale and no white had to be added after step 8. I have no valid explanation for the phenomenon yet, but maybe the red in this case has a slightly darker tonal value than the blue, so when having got rid of the difference by mixing in white for a while, the adding of more blue would not make any further changes to the overall tonal value. Or it may be my eyes, which are not yet expert at recognising small tonal differences with certainty. However, although I can see some fluctuations, I am quite pleased with the outcome. Considering the differences in darkening through drying in different hues of acrylic paint I was surprised to see a relatively smooth result. The brownish grey I was supposed to see halfway through the red to blue scale according to the study guide was not really there apart from the third mix from the left, but I may have msjudged the amount of colour to mix in in the first step, so there is a chance of having missed some information here simply by low resolution.

Exercise 3: Broken or tertiary colours

In the last exercise, requiring the mixing of secondary colours, the occurrence of grey was perfectly visible in the case of a scale between orange red to green blue, but was completely missing in the transition from sap green to vermilion. Maybe the mustard colours to the right of the sap green count as broken or tertiary colours without being grey. They certainly lack chroma when compared to the original colours (Fig. 9).

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Figure 9. Mixing secondary colours while keeping tonal values constant: top – orange red to green blue, bottom: sap green to vermilion

A phenomenon I noticed in all the mixing experiments was the different qualities of the colours chosen to mix, which resulted in skewed transitions in some instances. For example, in the mixing of primary colours the transition from yellow to red was fast, so that most of the scale I would describe as reddish. The same effect was visible in e.g. the transition from yellow to blue shown in the second photo from the bottom, second row, and in the last of all mixes from sap green to vermilion. I would tend to describe the scale as orange-dominated. It would be interesting to have other people look at the scales to see whether their perception matches my own.
Experimenting in this way was a major hint regarding both the incredible properties of colour and the power of human perception. It also makes my head swim to think of the worlds I need to discover yet. No wonder we are all addicted to colour.

References:

Lacher-Bryk, A. (2017) ‘Research point: Chevreul’s colour theory’ [blog]. Andrea’s OCA painting 1 blog, 3 Apr. Available at: https://andreabrykocapainting1.wordpress.com/2016/04/03/research-point-chevreuls-colour-theory/ [Accessed 20 February 2017]