The perfect complementary colours? Burnt sienna and ultramarine blue

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If you’ve taken a look at some of the posts on my blog, you can probably figure out that I enjoy learning about acrylic paint colours and how they can be used together. One colour combo that I particularly love is burnt sienna and ultramarine blue.

The two mix to easily create a beautiful, dark grey, along with a range of warm or cool greys. I like to do practice paintings with them because I don’t have to think too much about my colour mixes – the two colours mixed never become muddy or displeasing to me.

Why do they create such a lovely grey? The two are complementary colours. Orange and blue are opposite on the colour wheel. Let’s say you start with some ultramarine blue. As you add burnt sienna, which is a type of orange, the colour mix becomes more and more grey until you add enough burnt sienna that it starts leaning more orange.

A series of colour mix swatches from ultramarine blue to burnt Sienna with two tubes of paint.

Painting using just burnt sienna and ultramarine blue is also a fantastic way to play with and practice colour temperature. If an object is directly lit, whether with sunlight or a lightbulb, the shadow side will lean blue. The lit side will, unsurprisingly, be a fairly warm temperature. You can use burnt sienna for the warm, lit side, and ultramarine blue for the cool, shadow side.

In this video demo, I use burnt sienna and ultramarine blue acrylic paint, along with titanium white to lighten the value as needed. The photo I’m using is a white mug on a white table with a white background. I am using this demo to also practice painting an image where I intensify colours that aren’t obviously there in the photo.

Watch me paint using burnt sienna and ultramarine blue acrylic paint on my YouTube channel.