The Top 5 Acrylic Color Mixing Mistakes and How to Fix Them

The Top 5 Acrylic Color Mixing Mistakes and How to Fix Them

If you’re an acrylic painter who’s frustrated by color mixing, trust me when I say you’re not alone.

After over a decade of working with acrylic paints, I’ve seen firsthand the unique challenges of color mixing with acrylic. Some of the reasons you’re struggling may be really obvious, while others might surprise you.

So today, I’m sharing the top five color mixing mistakes I see with acrylic painters and how you can fix them.

If you found this useful, you can also download my free 36 page Introduction to Acrylic Painting eBook, which covers all things acrylic (did I mention it's free?). 

5. Using Too Many Colors

This might sound counterintuitive, especially if you’re just getting started. After all, isn’t it easier to use premixed colors instead of mixing them yourself? Why bother to mix an orange or turquoise if you can just use them straight from a tube?

But what I’ve discovered is that the more experienced you are, the fewer colors you actually need, and the stronger your paintings will become as a result.

Using fewer colors leads to better color harmony, which means all the colors in your painting are visually pleasing and cohesive. Many professional artists use what’s called a limited palette, which consists of a small selection of colors that work together to create a unified painting.

One famous example is the Zorn palette, which included yellow ochre, a warm red (often vermilion or cadmium red), ivory black, and white. Contemporary painters like John Pototschnik often use just one red, one yellow, one blue, and white, sometimes adding an earth tone like burnt umber.

If you find that your colors are clashing, take a look at your palette. Are you using too many premixed secondary colors like oranges, greens, and purples? If so, you might be accidentally introducing colors that don’t work well together.

To fix this, try limiting your palette to just one red, one yellow, one blue, and possibly an earth tone. This will help you achieve much better harmony in your paintings.

My personal favourite: a cool red (like quinacridone magenta or alizarin crimson), cadmium yellow (either medium or light, depending on the value I need), ultramarine blue, burnt umber and titanium white. 

4. Not Knowing the Undertones of Your Colors

When you walk into an art store for the first time, the number of paint options can be overwhelming. You might expect to find just a basic red, yellow, and blue, but instead, you see names like phthalocyanine blue, quinacridone magenta, and naphthol red.

The reason for this is that primary colors don’t exist in a single, pure form. Instead, they lean either warm or cool:

• Warm primaries: Reds that lean toward orange, yellows that lean toward orange, and blues that lean toward red.
• Cool primaries: Reds that lean toward purple, yellows that lean toward green, and blues that lean toward green.

If you want to mix a vibrant purple, for example, you need a red with a blue undertone (like quinacridone magenta) and a blue with a red undertone (like ultramarine blue). But if you mix a red that leans toward orange (like cadmium red medium) with ultramarine blue, you’ll get a muted, muddy purple instead.

To fix this issue, take the time to learn about the undertones of your paints. If you need a vibrant color, mix two colors that lean toward each other on the color wheel. If you need a muted color, mix colors that lean away from each other.

The above image is from my course, Color Mixing with Acrylic, which launches March 28th, 2025! You can get on the waitlist for a special discount by clicking the link.

3. Not Knowing Your Opacity Levels

Opacity refers to how transparent or opaque a paint color is. Transparent colors allow the colors underneath to show through, while opaque colors provide solid coverage.

Each pigment has its own natural opacity level. You can usually find this information on the paint tube:

• An empty square means the color is transparent.
• A half-filled square means it’s semi-transparent.
• A solid black square means it’s opaque.

A transparent color isn’t a bad thing—it can actually be used to create beautiful layering effects. For example, layering a transparent color like quinacridone magenta over a bright yellow will result in a glowing orange.

If you need better coverage, you can mix a transparent color with an opaque one, or layer multiple coats of transparent paint until you reach the desired opacity.

2. Not Realizing Acrylic Paint Dries Darker

One of the most frustrating things about acrylic paint is that it dries darker than it looks when wet. This is due to the way the binder in acrylic paint becomes more transparent as it dries.

If you’re mixing colors and they look perfect while wet, but appear too dark when dry, you’re not imagining it—it’s a real phenomenon.

To compensate for this, try mixing your colors slightly lighter than you think they should be. With practice, you’ll get a better sense of how much to adjust your mixes.

Another trick is to do a test swatch before committing to a full painting. Apply a small amount of paint to your surface, let it dry, and see how the color changes. This can help you adjust your mixtures before you use them in your artwork.

1. Only Using White, Grey, and Black to Adjust Your Colors

A common mistake in acrylic color mixing is relying only on white, grey, or black to adjust the value of a color. While these can be useful, they can also dull your colors.

For example, adding white to darken a color can make it look chalky or bleached, and adding black can make it look muddy. Instead, try using complementary colors to adjust value and saturation.

If you want to darken a yellow, instead of adding black, try mixing it with a deep red or burnt umber. If you want to lighten a red, instead of adding pure white, mix in a bit of yellow to keep it warm and vibrant.

By understanding how colors interact, you can maintain the richness and vibrancy of your paintings without unintentionally dulling your colors.

Above is the complementary opposites spread from my Color Mixing with Acrylic course, which demonstrates how you can darken yellow by using purple. 

Final Thoughts

Color mixing with acrylic paint can be challenging, but by avoiding these five common mistakes, you’ll gain much better control over your palette. Remember to:

• Limit your colors to create harmony.
• Pay attention to undertones for cleaner mixes.
• Understand your paint’s opacity levels.
• Adjust for acrylic paint drying darker.
• Use complementary colors instead of relying solely on white, grey, and black.

If you found this helpful, I’m releasing a color mixing course specifically for acrylic painters. In this course, I teach you everything I know about mixing colors with acrylic, and we work through 26 pages of real-time exercises together. You can find the link to the course here, and it launches March 28th!

Happy painting!

If you liked this blog post, check out my other posts on Acrylic Painting:

Color Mixing with Acrylic: Why Acrylic Paints Dry Darker

The Three Dimensions of Color: Hue, Value and Chroma

You can also check out the YouTube video here: