Understanding Colour: Primary and Secondary Colour Mixing

Key: PYD = Primary Yellow Dark, PY = Primary Yellow, LY = Lemon Yellow
NY = Naples Yellow, YO = Yellow Ochre, SR = Spectrum Red, PR = Primary Red
CR = Crimson, VE = Vermillion, BR = Bright Red, CE - Cerulean, PB = Primary Blue
UL = Ultramarine.

The first step in this exercise was to identify the differences in tone, hue and chroma between the yellows, reds and blues taken directly from the tube. I decided to use gouache for this exercise as I had a wider range of colours to choose from. However, I had two different qualities of gouache. The Windsor and Newton Designers Gouache was of better quality than a pack of Daler Rowney 'Simply Gouache' - these paints had a larger amount of 'filler' compared to pigment and were consequently less intense and more difficult to handle - I won't buy them again. 

All of the yellows were relatively light in tonal value. The primary yellow appeared to be the lightest but its value was quite similar to the lemon below and naples yellow. The Primary Yellow Dark and the Yellow Ochre were darker in value than the remaining yellows but nowhere near as dark as any of the reds or blues. 

Lemon yellow had a touch of green to its hue and this became more noticeable when it was placed adjacent to the Primary Yellow Dark and Yellow Ochre which have an orange and a brown component to them respectively. Naples yellow appeared to be very slightly more orangey than primary yellow but was significantly less intense. 

Lemon Yellow and Naples Yellow were the least intense of the yellows - this may also have been a result of these being the poorer quality paints. Primary Yellow was the most intense so I chose this as my primary yellow.

The reds were more mid-range in total value. Vermillion appeared to be lighter in tone than the rest of the reds but the rest were fairly similar in tone.

Vermillion tended towards the orange end of the spectrum. Crimson was the red containing the most blue. Primary Red and Bright Red also contained a hint of blue. 

Primary Red and Spectrum Red were the most intense reds but I chose Spectrum Red for my primary red as it was less blue.

There was a range of tonal values amongst the blues. Cerulean was the lightest and ultramarine the darkest blue. 

Both Cerulean and Primary Blue showed some greenness whereas ultramarine tended more towards purple. Ultramarine was the most intense blue but had too much red in it to represent a true primary blue so I mixed my idea of a primary blue from a combination of Ultramarine and Primary Blue. 

At the bottom of this sheet I mixed a scale from yellow through to red. However it wasn't  until after I'd done this that I realised I had used PYD instead of PY. I had subconsciously picked up the most orange yellow when mixing this scale.

Key: PY = Primary Yellow, SR = Spectrum Red, PB = Primary Blue,
UL = Ultramarine, VIO = Violet, CR = Crimson, PR = Primary Red
MA = Magenta, WH = White

Next I used my chosen primary colours to mix secondary colours. Yellow to Red, Yellow to Blue and Red to Blue. I made too many gradations at the yellow end of the yellow to blue gradation so didn't leave much space for darker and bluer greens at the other end. The red and blue mixture did not produce violet but more of a burgundy/maroon colour. A better violet was produced by mixing ultramarine with either crimson, primary red or magenta. 

The next task was to repeat these three graduations but to mix white into the darker toned colours to try to maintain a constant tonal value. I found this very difficult to judge - the different colours confused me as regards tonal values - looking at the ranges afterwards It looked to me as though the tones got darker from left to right and then I over compensated with too much white in the blue at the right side. I took a photograph of this sheet in black and white to asses this.

It was clear from this that there was a slight graduation from light to dark on the yellow to red graduation (not enough white added to compensate for the darkening caused by the addition of red). In both of the others I had over compensated by adding too much white to the blue at the right side.