The Four Most Common Causes, Tested with Soft and Oil Pastels
Introduction
You start with beautiful, saturated colors. A few layers later the painting looks gray, flat and lifeless, and you are not entirely sure when it happened.
This is one of the most common frustrations with pastel, and the good news is that it usually comes down to four causes. I tested each one on paper, using both soft pastels and oil pastels, so you can compare what happened here with what is happening in your own work.
Once you can identify which of the four you are dealing with, the fix becomes obvious. If you are new to pastel in general, Pastels for Beginners: Unlocking the World of Pastels covers the fundamentals first.
1 - The Quick Answer
Four things turn pastel muddy or dull:
Too many layers. The paper surface fills up and stops accepting new pigment.
Too many colors mixed together. Several colors combined become a dirty gray.
Over-blending. Working the same area too much flattens the color and damages the paper.
Complementary colors meeting by accident. Opposite colors blending at a boundary create a muddy neutral.
Each one is covered below, with what I saw when I tested it and what to do about it.
2 - Cause 1: Too Many Layers
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| Left, soft pastel. Right, oil pastel. Both reached a point where more layers added nothing. |
For this test I used both soft pastel and oil pastel, applying them directly with the stick and also by scraping, which gave me four versions in total. Every one of them reached a point where it was no longer possible to add more color. Beyond that point, all I was doing was wasting material.
More layers do not necessarily mean more saturation. There is a point where adding another layer only wastes pigment, and it can even create unwanted marks on the surface. This happens because the tooth of the paper fills up, which I explain in more detail in Best Paper for Pastels, where I tested five different surfaces.
How to fix it. Work with a plan. If you reach a point where you would like to go further but you can see the surface has hit its limit, often the best thing to do is nothing at all. And if your goal was to darken the color, adding more layers of the same color will not get you there. Add a complementary color instead.
3 - Cause 2: Mixing Too Many Colors
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| Too many colors in one place, and everything turns to mud. |
Here I added several different colors, again testing both soft and oil pastel. With the soft pastel, I used cotton to blend the loose dust coming off the various colors.
In both cases the result was the same: a color close to a dirty gray, almost the color of mud.
How to fix it. Planning is essential to get the best out of the material. Decide which colors are going into an area before you start, and keep the number small. If you want a specific tone, mix it deliberately rather than letting colors accumulate by accident.
For a deeper look at how colors neutralize each other, this guide to mixing neutrals explains the principle in watercolor, and the logic applies to pastel too.
4 - Cause 3: Over-blending
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| Top, blending directly on the paper. Bottom, the same lilac mixed in a dish first. |
For this one I used pink and blue soft pastel to create a lilac.
In the first example I applied both sticks directly to the paper and tried to blend my way to the tone I wanted. The more I blended, the harder it became to reach it, and the more I tried, the worse it got. Rubbing the paper repeatedly changes the surface and eventually damages it.
How to fix it. My suggestion is simple: use the scraping method. Here I scraped both colors into a small dish with a blade and mixed them there, testing until I reached the exact lilac I wanted.
A useful tip on mixing this way. If I want a pinker lilac, I start with pink and add blue gradually. If I want a bluer violet, I start with blue and add pink. Building the tone in that direction means you avoid wearing down the paper more than necessary to arrive at the color you were after.
For a full comparison of blending tools and application methods, see How to Blend Pastels.
5 - Cause 4: Complementary Colors Meeting by Accident
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| Where opposite colors meet, a muddy neutral appears. An eraser can lift some of it back. |
For this test I used soft pastel only, with two different color combinations. In both cases the result was basically the same: a dirty neutral tone forming at the boundary between the colors.
This means extra care is needed when blending near an area where two opposite colors meet.
How to fix it. If you notice it has already happened, do not try to blend more in the hope of improving the situation. Stop immediately. A good option is to use an eraser or a kneaded eraser to lift the excess pigment. Avoid rubbing hard, so you do not damage the paper. Remove what you can and work from there.
6 - A Practical Example: Fixing It in a Real Painting
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| The blue leaf was too dark. A light touch with the eraser brought the intensity back down. |
Here is what this looks like in practice. In this floral drawing I used oil pastel, and I found the blue leaf far too dark. I was able to lighten it using an eraser, working lightly and simply reducing the intensity of the color.
This is one of the things I appreciate most about oil pastel, and I wrote about it in Oil Pastels for Beginners. An eraser gives you a genuine second chance, as long as you use it gently.
7 - How to Prevent It
Most of the fixes above are easier to apply before the problem appears than after. Four habits make the difference:
Plan the colors for each area before you start. Knowing which two or three colors go where prevents most accidental mixing.
Mix your tones in a dish rather than on the paper. Scraping colors into a small container and testing there means the paper only receives the color you already decided on.
Work from light to dark. It is far easier to deepen a color than to bring it back once it is too dark.
Stop before the surface fills up. Watch for the moment when new pigment stops adhering, and treat that as the limit rather than something to push through.
8 - On Coloring Pages
Printed coloring pages make all four causes more likely, for one reason: standard printer paper is smooth and holds very little pigment, so the surface fills up much faster than on textured paper. What would take six layers on mixed media paper might take two here.
The practical answer is to print your pages on paper with more texture, such as mixed media or drawing paper, which I compared in the paper test linked above. Beyond that, the same habits apply: fewer colors per area, tones mixed in a dish before they touch the page, and a light hand when blending.
If you would like well-designed floral pages to practice on, the Original Floral Designs Coloring Book offers 72 hand-drawn floral coloring pages you can print on the paper of your choice.
Final Thoughts
Muddy pastel is almost never a skill problem. It is a surface that filled up, too many colors in one place, too much blending, or two opposite colors meeting where you did not plan for them to meet.
The single habit that prevents most of it is mixing your color before it reaches the paper. Once you build tones in a dish and apply them deliberately, the paper stops being the place where you experiment and becomes the place where you paint.
Have you run into any of these? Share your experience in the comments!
