When we talk about color mixing with acrylic, most of the focus tends to fall on hue and value. But there’s another crucial element that often gets overlooked - opacity.
If you've ever mixed what seemed like the perfect color, only to apply it and find it looks completely off, chances are the issue wasn’t your mixing. It was the opacity of your paint.
Let’s take a deeper look at how opacity impacts your acrylic paintings...and more importantly, how understanding it can seriously level up your color mixing.
Before we start, if you'd like to download my FREE 36 page Introduction to Acrylic Painting eBook, you can do so here. Tens of thousands of artists have downloaded the eBook to date, and I'd love to send it to you for free!
What Is Paint Opacity?
Every tube of acrylic paint has an inherent opacity level, ranging from opaque to transparent. This is determined by the pigment used and its chemical makeup. For example:
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Highly opaque colors: Titanium white, cadmiums, burnt umber
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More transparent colors: Quinacridone magenta, ultramarine blue, phthalo colors
Knowing which is which can save you a lot of frustration later, especially when layering.
How Opacity Affects Color Mixing with Acrylic
Acrylics are all about layering. And if you don’t factor in a color’s transparency, it doesn’t matter how perfect your mix is: it might not behave how you expect.
Let’s say you mix ultramarine blue and try to layer it over a dark background. If you’re using it straight from the tube, it won’t cover well. It ends up looking more like a colored glaze than a solid area of color. The layer underneath shows right through.
Layering for Success
If I want that same ultramarine to show up boldly on top of something dark, I need to give it support. Here’s what I do:
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Mix in a touch of titanium white to make the ultramarine more opaque.
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Apply that mixture as a base layer and let it dry fully.
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Glaze pure ultramarine blue on top.
Now it reads the way I want it to, and that’s the power of understanding opacity.
Transparent Colors and Visual Mixing
Here’s another real-world example I show in my color mixing with acrylic course. I lay down a stripe of quinacridone magenta over two different dry background colors:
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One is cadmium yellow light
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The other is a green mixed from cadmium yellow light and ultramarine blue
Same magenta on top, but you get two totally different results. That’s because with layered transparent paints, you’re not mixing pigments - you’re mixing light that's reflecting off of both colors together. The eye is blending the colors visually.
This is a fantastic way to build depth, dimension, and luminosity in your work.
For a full video explanation of this, head over to my YouTube video, Top 5 Acrylic Paint Color Mixing Mistakes (and How to Fix Them):
Layering = Professional Results
Instead of trying to mix the exact right color in one go, think of your painting in layers. Maybe your base layer is a deep burnt umber, and you want to add warmth on top. Using a transparent red over it can create a glow that a single flat layer never could.
When done thoughtfully, layering transparent and opaque paints gives you a richer, more dynamic result. It’s what gives acrylic paintings that professional finish.
Solving Streakiness in Acrylic Paint
One of the most common frustrations I hear from beginners is streaky brush strokes, especially with more transparent colors. But this isn’t a mistake or a bad tube of paint.
Transparent colors naturally show more brushwork because they let the underlying layer shine through. Opaque colors tend to hide brush strokes more effectively.
How to Fix It
If streakiness is getting in your way, simply build up your color in multiple thin layers. Each additional layer helps reduce visible brush marks and evens out the finish.
Why I Teach Opacity Early in My Course
This is exactly why I introduce paint opacity right at the beginning of my Color Mixing with Acrylic course. When you understand how and why paints behave differently, you can use that knowledge to your advantage—and stop blaming yourself when things don’t look right on the first pass.
If you’ve been struggling with coverage, layering, or getting the right color on canvas, chances are it’s not your fault. You might just need to consider the opacity of your paint.
Final Thoughts: Think in Layers
If there’s one takeaway here, it’s this: color mixing with acrylic isn’t just about hue and value. It’s also about how your colors behave in layers.
By understanding the opacity of your paints - and how to layer them effectively - you’ll unlock a whole new level of control and confidence in your work.
And if you want to dive even deeper into building your skills with intentional color choices, layering strategies, and mix-by-mix guidance, my course was made with you in mind.
PS If you found this useful, you should definitely check out my brand new Color Mixing with Acrylic course. It's over 15 hours of instruction, with 70+ lessons and lifelong access to our online painting community. Check it out here.
If you enjoyed this blog post, check out this blog post: How to Mix Colors in Acrylic: a Beginner Friendly Guide
You can also check out my Acrylic Color Mixing Guide for easy tips on mixing vibrant acrylic colors.
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