Soft Pastel Colour Mixing: How to Avoid Mud

Why Is My Painting Getting Muddy?

This might sound familiar to many pastel painters: you are working on a pastel painting, adding a little colour here and another colour there, and somehow the beautiful colours you started with have turned into something dull, greyish and, well… mud.

Obviously, there is nothing wrong with muddy colours. Greys, browns and all sorts of muted colours can be absolutely beautiful and we need them in our paintings. The problem arises when you didn’t actually want that colour. You wanted a glowing skin tone, a fresh green or a subtle blue-grey, and ended up with something resembling dishwater instead.

Usually, the culprit is quite simple: too many colours have been mixed together.

Mixing Pastel Without Making Mud

Pastel is different from wet paint. With oil or acrylic paint you can mix colours together on your palette until you have exactly the colour you want. With soft pastel, we don’t have a palette in quite the same way. We mix our colours on the painting itself.

There are various ways of doing this, but my favourite method is by layering marks over each other, often using hatching. I might put down a series of strokes in one colour and then hatch another colour lightly over the top. Seen from a little distance, the colours visually mix. It is a little like Pointillism: your eye does some of the mixing for you.

You can do the same thing with larger marks. Use the long side of your pastel stick to make broad strokes and then layer another colour lightly over the top.

The important word here is lightly.

If you press hard with your pastel, you will quickly fill the tooth of the paper. Once all those little hills and valleys in the surface of your pastel paper are filled with pigment, there is nowhere for the next layer of pastel to go. Colours start sitting heavily on top of each other and it becomes increasingly difficult to adjust what is there.

Working lightly keeps your options open.

Be Careful How Many Colours You Add

If a colour isn’t quite right, the temptation is to keep adding things to it.

Perhaps your skin tone is too warm, so you add some blue. It still isn’t quite right, so you add a little green. Now it looks too cool, so you add some red. Perhaps a little yellow will bring some warmth back …

Before you know it, you have five or six colours sitting on top of each other and the result is a rather nondescript grey-brown.

This is also what happens when mixing wet paint. Mix enough different colours together and eventually you will end up with a neutral colour. With pastel, the mixing might be less thorough, but the same principle applies.

So stop and think before reaching for yet another pastel stick. What does this colour actually need? What do I need to do to get there?

If a skin tone is too warm, for example, I might lightly hatch or dab a little blue over it. I don’t necessarily want to cover the colour underneath. I want the blue to work with it and cool it down.

If the colour is too cool, I might add a little ochre or sienna. Again, I am not trying to completely cover up what is already there. I am adjusting it.

Often, one carefully chosen colour is enough.

Blending

Another way of mixing pastel colours is, of course, blending. You can rub the colours together with your finger, a blending tool or any number of gadgets sold for the purpose. Personally, I am not a fan of this technique, but each to their own.

Blending pastel tends to create flat, smooth areas of colour. It gets rid of the individual marks and the interaction between colours that makes pastel so lively. In limited amounts it can work wonders and create a nice contrast with more painterly sections. Many painters use blending for portrait backgrounds for example. But for mixing colours while blending the  same system applies: lightly layer another colour over it, blend, and see what happened. Blending fills the tooth of the paper even faster, so you’ll have to really be careful with what colour you add. Too many colours and the MUD is back.

I prefer hatching as it keeps the tooth open and provides a texture that you can vary from near smooth to quite expressive.

If you hatch blue over a warm brown, both colours remain present. Up close you can see the individual marks; from further away they come together into something new. There is much more life in that than in rubbing the two colours together into a uniform third colour.

It also gives you much more control. You can add just a few blue marks and see what happens. If you need more, add a few more. You can gradually steer the colour in the direction you want without destroying what was there before.

Don’t Fill the Tooth Too Soon

Muddy colour is not always just about colour choice. Sometimes it is also a sign that you have simply put too much pastel on the paper.

Pastel paper can only hold so much pigment. If you start your painting with thick, heavy layers, you leave yourself very little room to make changes later.

This is one of the reasons I work lightly, especially in the earlier stages of a painting. I want to preserve some of the tooth of the paper for later layers.

As the painting develops, I can gradually add more pastel and increase the pressure where I need to. But if I have already filled the paper with pastel at the beginning, trying to change a colour later becomes much more difficult. The new colour will struggle to grip the surface and you may find yourself pressing harder and harder, adding yet more pigment and making the problem worse.

So What Do You Do If Your Pastel Is Already Muddy?

First: stop adding colours.

Have a look at the area and decide what colour you actually want it to be. Is it too warm? Too cool? Too grey? Too dark?

Then choose just one colour that will move it in the right direction. Try it out on a separate piece of paper first if unsure.

Add that colour lightly. Hatch it, dab it or make a few larger strokes with the side of the pastel. Don’t immediately cover the entire area. Let the new colour interact with what is already there and step back to see whether it is doing what you want.

If the paper is already completely clogged with pastel, you might have to remove some pigment before continuing. But ideally, by working lightly and resisting the urge to keep throwing more colours into the mix, you won’t get to that stage very often.

And remember: a muted brown, grey or muddy green is not necessarily a bad colour. Paintings need quiet colours as much as they need bright ones. The problem isn’t mud itself. The problem is getting a colour you did not intend.

Keep your touch light, keep some tooth in your paper, let your pastel marks remain visible, and think about what a colour needs before adding another one. Your colours will stay much fresher — and you’ll have far more room to change your mind as you paint.

Disclaimer: The links in this post are affiliate links to Jackson’s art materials shop. You do not pay anything extra but will support this blog by purchasing your art materials though these links. AI was used to create the image with the mixing samples.