One of the worst surprises when pouring acrylics is that our colours mix too much and become dull and muddy.
Why do colours become muddy when poured?
The reason for this is that the colours are moved around during the pouring process until the canvas is completely covered (tilting). In this process, the colours mix together and, if they are complementary, they tend to neutralise each other and the end result is a dull brownish colour.
Below you will find some key-concepts from colour theory that better explain this process.
Basic concepts from colour theory
Transparency or opacity of the colour
As already explained in another article, not all colours have the same opacity. They can be opaque, semi-opaque, semi-transparent and transparent. While the opaque colours are more suitable for acrylic pours as they retain their strength after drying, semi-transparent and transparent colours are a little more difficult to use as they allow other colours underneath to show through after drying and mix more easily with other colours. This means that if you have a transparent green on top of an opaque red, for example, the colour combination could look brownish and dull.
Interaction of complementary colours
In addition to the concepts of transparency vs. opacity and colour strength, the interaction of complementary colours plays an important role in the selection of our colours.
By definition, complementary colours are pairs of colours that are opposite each other on the colour wheel (e.g. purple/yellow, red/green, blue/orange).
For this reason, they form a stronger contrast to each other than any other colour and, when placed next to each other, make each other appear brighter. Unfortunately, when complementary colours are mixed together, they tend to neutralise each other, creating dull colours (grey or brown tones with a tendency towards black or white), and when this happens, your work loses brightness.
In order to see whether our colours are complementary to each other, you can either look at the position of the pigments they contain on the colour wheel by B. McAvoy or the colours themselves on the colour wheel of a colour mixing model.
Relative vs absolute colour
The former are the colours as you see/feel them, the latter are the colours as they are. Relative colours are interesting because you can perceive them lighter or darker depending on the value and intensity of the colours you place next to them. (See also the tutorial Quick Tip 254 - Relative Color by Dianne Mize “In The Studio Art Instruction” )
Colour bias and colour temperature (warm vs cold hues)
The term "colour bias" describes the tendency of a colour to lean towards a primary, secondary or other colour on the colour wheel (e.g. a reddish violet or a greenish blue).
In this context, it is also important to remember the concept of colour temperature, i.e. how we perceive a colour in relation to its temperature (warm / more yellowish/reddish - cold / more bluish).
As a rule, there is a warm and a cold version of each colour and, in order to obtain clean mixing results, colours with the same temperature should be combined with each other. However, if you mix cold and warm tones together (for example, a cold blue with a warm red), you will sometimes get a neutral tone for the resulting colour (in our example, a greyish dark violet).
Knowing the colour bias can be very important in the creation of bright or dull colours (See also Tutorial by Livia Dias Studio and Tutorial by Dianne Mize “In The Studio Art Instruction” ).
In the following paragraph I will list some strategies that can help to avoid muddy colours through acrylic pouring.
Strategies to avoid dull (muddy) colours through acrylic pouring
1) Use one or more primaries between the two complementary colours as intermediate colours:
E.g.: Red - Yellow - Green
E.g.: Purple - Blue - Green - Yellow
E.g.: Blue - Red - Orange - Yellow
E.g.: Yellow - Green - Blue
E.g.: Orange - Red - Magenta
2) Make transparent or semi-transparent colours thicker or mix them with a very small amount of titanium white
If transparent colours are thicker or contain a small amount of titanium white, their opacity improves and they could be used like normal opaque colours.
3) Insert a layer of white between the complementary colours when you want to keep them well defined and avoid them from blending.
4) Alternate light and dark shades to achieve greater contrasts
E.g.: Turquoise Pastel / Turquoise / Blue Pastel Blue / Dark Blue / Violet Dark Violet
5) Use colours that are in the same area of the colour wheel to get more harmonious results
E.g.: Red / Orange / Yellow
E.g.: Yellow / Green / Blue
E.g.: Red / Magenta / Blue Tones
E.g.: Red / Magenta / Purple Tones
E.g.: Green / Turquoise / Blue Tones
E.g.: Green / Turquoise / Purple Tones / Magenta
Conclusions
To summarize, the brightness of our paintings depends on different factors such as colour temperature, colour bias and the elementary rules of colour theory for mixing.
I hope this tips will help you to improve the choice of the colours for your paintings. Let me know in the comments if it was helpful and/or if you have found any other strategy to help you in avoiding muddy colours.
Thank you for reading. If you like the post, feel free to leave a like, a comment and don’t forget to follow my blog, my Instagram and share the content on your social media.
Have a colourful and creative day!
Laura