Colour is one of the most crucial tools we have to turn a normal chart into a powerful chart with a clear message, a chart which tells a story rather than simply presenting the information.

This Venn diagram shows the number of harmful pesticides, presented as dots, banned or phased out in four major economic regions (Brazil, the United States, Europe and China).

Notice how colour is used in three different ways here.

Background colours

Grey is used as a background colour– elements in grey are present and visible, but they will never be at the foreground of the visual, or get in the way of the key message. Used in a clever way, grey can help our viewer to distinguish between what’s most and what’s less important, and bring structure to the layout of the visual.

In fact, most of the time it’s a good idea to create the first version of your data visual purely in tints of grey. This will help you to quickly see if your design will work, and how your data visual will be perceived.

Thematic colours

Blue is used as a thematic colour – because we associate the European Union with the colour blue (because of its flag and logo), it is a logical choice to use this colour to indicate everything related to Europe. Blue is not only used for the dots and the Venn diagram, but also the number 169 in the label, and the words ‘Europe’ and ‘European Union’ in the title and label. This helps to tie all the different parts of the image – diagram, title and annotations – together in a logical, visual way.

Accent colours

Finally, red is used as an accent colour – it almost automatically draws our attention to the central part of the visual: the 10 harmful pesticides which are banned in all four major economic regions simultaneously. Make sure to use your accent colours sparingly. As they are so good at drawing attention, using too much of them will quickly overwhelm your audience – they won’t know where to look first! Highlight only the elements which are crucial to explain your key message.

If you want to know more about visualizing data in the right way, you can check out the other videos in this series. Or I invite you to read my book, Powerful Charts, that will give you actionable insights and practical guidelines to create data visuals that truly engage and inspire your audience.