All colours can be mixed from the Primary colours… well, in theory.
There is no need to buy lots of different paint colours. You can mix almost every paint colour you will ever need from Cadmium Red, Cadmium Yellow Mid, Phthalo Blue (short for Phthalocyanine) and White. The only drawback from this is that when paint pigments are mixed they lose a little intensity and, depending on the quality of the pigment, you will struggle to mix the secondary colours at their most vibrant. The good news is you will rarely need these in painting.
Red and Blue are not Primary colours.
I know I just said Red, Yellow and Blue could mix almost all the paint colours you will need, and this is still true. However technically the real Primary colours are Cyan, Magenta and Yellow. Like in your printer. Yellow and Magenta ink mix to create Red, and Cyan and Magenta create the Blue we are familiar with as a darker Blue. If you have ever struggled to mix a vibrant Purple from Red and Blue paint, this is the reason. Try mixing a Magenta paint with Cyan or Blue and see the difference. You can even mix a pretty good Red from mixing Magenta paint with Yellow. I always have a tube of Magenta paint in my kit, but I rarely need or use it. It’s good to understand the true theory of primary colours to get the most out understanding colour theory and help you solve some tricky colour situations, but in reality you can still mix almost all the colours you will ever need from Red, Yellow and Blue. I’ll refer to them as primary colours for the rest of this list based on painting tradition.
The truth about secondary colours…
Secondary colours are created from mixing two of the primary colours together. Commonly known as Orange (Red + Yellow), Green (Yellow + Blue) and Purple (Blue + Red). They extend along the colour spectrum from one primary to the next, right from the first bit of Yellow added to Red, through Red based Oranges, Orange, Yellow based Oranges all the way to the last bit of Red added to Yellow. Most of the Internet will try to tell you different, referring to some of these mixes as Tertiary colours. Ignore that.
Tertiary colours contain all three primary colours.
When small children paint and mix up all of their paint it always ends up a Brown, Olive or if equally balanced, a neutral Grey, but these are not the only tertiary colours. Tertiary colours, also known as tones, make up the majority of colours used in great paintings. A blue sky will contain small amounts of Red and Yellow. A pinkish skin tone will also contain small amounts of Blue and Yellow. Tertiary colours can be used to create balanced, harmonious and cohesive paintings as well as used to enhance contrast, vibrancy and luminosity. Paintings without tertiary colours can appear childlike, as the colour mixing is quite simplistic.
Most of the paint colours for sale are tertiary colours that you can mix yourself with the three primary colours.
If you only remember one thing from this list – make it this one.
Mixing all three primary colours together creates a neutral grey.
A neutral grey is a tone that doesn’t favour any colour on the spectrum. This is achieved by mixing Red, Yellow and Blue in equal amounts in regard to the strength of the pigment, rather than by quantity.
All colours are not created equal.
This is not about favouritism, but more technically about how strong the pigment is. For example a small amount of Phthalo Blue will have a much greater effect when mixed with a larger amount of Cadmium Yellow than the other way around. Learn to mix your paints by eye rather than a formula. You will get used to how strong each pigment is. Add a bit at a time until you get used to how much you need. Build up slowly. It’s much easier to add more than try and remove too much.
Complimentary colours create contrast.
Complimentary colours are on opposite sides of the colour wheel. They are complimentary not because they go well together, but because they emphasise the colours hue due to the contrast from comprising of strikingly different ingredients. A Red (Primary) is opposite to Green (Yellow and Blue) on the colour wheel and they share no ingredients in common. A Red will seem even more red when viewed next to Green and vice versa. The same goes for complimentary pairs of Yellow (Primary) and Purple (Red and Blue), and Blue (Primary) and Orange (Red and Yellow).
Complimentary colours are a great way to desaturate colours.
Mixing complimentary pairs together can achieve a dark neutral grey, because between them they contain all three primary colours. If you are trying to knock back the vibrancy of a colour, the simple solution is to add a slight amount of the complimentary colour. This creates a tertiary mix of all three primary colours. This may need to be balanced tonaly by adding a some white to mantain the same lightness. Tertiary colours are a necessity in structuring and creating space in your painting. For example a less vibrant colour (desaturated, tertiary or tone) will recede from the viewer, seeming to be further back, and a more vibrant colour will advance, coming forward toward the viewer.
White paint desaturates colour.
When white paint is added to primary and secondary colours they become tints or pastels. When white is added to tertiary colours they become lighter tones. These lighter tones are essential in painting. Muddy Brown tertiary tones become beautiful skin tones when white is added. You can create complex colour effects in your paintings by placing different tertiary colours of the same lightness next to one another. These lighter tones can contrast from warm to cool or be complimentary or analogous (similar area of the colour wheel) colour schemes.
If you are mixing very light tones you may need to add more colour to compensate for desaturation. Adding white will also increase the opacity of you paint as good quality pigments are quite transparent to achieve maximum saturation or chroma.
Black paint kills colour.
Don’t use Black paint in your painting… unless absolutely necessary. The strength of the pigment, in black paint, over powers any colour it is mixed with leading to drab and dull colours and paintings. Technically when you add black paint to primary and secondary colours they become shades and when added to tertiary colours they become darker tones. Unfortunately, in reality, adding black paint reduces the colour differences between the tones. In practice, the three primary colours mix to a very dark grey that will more than suffice for the majority of darker tones you will need in a painting. The added benefit of mixing your own dark tones is that you can vary the colour bias from warm to cool or complimentary mixes to create contrast and interest in your darker areas.
What specific Primary colours you should buy.
There are many hues of red, yellow and blue available to purchase, so which ones to choose? You should aim for primary colours that don’t strongly favour secondary colours. Cadmium Red, Cadmium Yellow Mid and Phthalo (Phthalocyanine) Blue are good reliable pigments for mixing complete colour wheels.
Some will recommend using primaries that are closer to the secondary you want to mix. For example a cool green biased blue mixed with a green biased yellow to create a vibrant green. This makes sense and will work well, unless you want to mix either of these with Red to achieve vibrant secondaries. The reason this is problematic is because all three Primary colours would be present in the mix leading the colour to be tertiary and less saturated. Having both a warm and cool version of each Primary can solve this, it just means buying more paint.
If you are unable to mix a vibrant Secondary to the desired chroma that you need, it may be easier and cheaper to just buy the Secondary instead.
Practicalities of mixing and applying paint.
Theory is one thing, but practice is where it counts. A lot of people like to start out painting cautiously watering down their paint to take things slowly. The problem with this is that the pigment is spread out and less effective. Watercolour pigments are specifically designed for this and the colours also benefit from the brightness of the paper showing through due to their translucency.
When painting with acrylics it is important to apply enough paint, especially on canvas. Colours in acrylic paint look more vibrant when there is more paint on the surface. Think of the desired consistency as a fluid cream that doesn’t have much resistance to the brush and expect to paint over your first layer of paint. Another way to increase the vibrancy of your paint is by adding a layer of gloss or semi gloss at the end, as acrylics can sometimes appear flat leading to dullness. It is also important to note that most acrylic paints dry a tone darker than when mixed, so you will need to mix colours a little lighter than the desired result. This is developed through practice and you can also use a hairdryer to speed up drying important test swatches.
One of the main ways to create vibrant colours is to maintain discipline in your work habits. Wash out your brushes thoroughly and consistently in between different colour mixes to avoid unintentionally introducing colours that lead to desaturating Tertiary mixes. Be sure to keep your colours separate on the palette and use a palette knife to add paints to your mix, wiping the palette knife in between, to avoid cross contamination. Also wipe down or clear off parts of you palette that are either drying out or you don’t plan on using again. You can’t expect to have control over your painting if your palette looks muddy and disorganised.