When you look at a colour wheel, the complimentary colours directly opposite each other on the colour wheel – red and green; blue and orange; yellow and purple.
Complementary colours when placed side by side are more vibrant. The key is to have one colour more dominant than the other. In this painting, the yellow/orange is the dominant and the subordinate colour is the purple/blue. I have also used complimentary red and green with the green being the dominant colour.
Also, when complementary colours are mixed together, they produce a neutral grey or black. The black created is a mix of complimentary colours in equal amounts. If the colours are not mixed in equal amounts, the black would lean toward one colour. With acrylic paints adding white produces a grey colour.
This painting is created using two colours only – complimentary colours – Ultramarine Blue and Burnt Siena (an orange). With watercolour, greys are produced by adding water.
To get a good handle on mixing complimentary colours create paintings using only complimentary colours – in this case use Ultramarine Blue and Burnt Sienna. Use the templates provided in my previous post – Understanding Colours – Value. You should already have a value scale of the Burnt Sienna. Print up two more of the value scales and create one using the Ultramarine Blue and on the other mix the Ultramarine Blue and the Burnt Sienna in equal amounts with the darkest value at the bottom and adding water to create lighter greys. Once this has been done, create a painting using only the two colours and the black/grey mix varying the values. You can use the tree stump template or a painting of your choice.