3 Ground Rules to Start with:
This rule may appeal less to a pictographic piece of information.
- No more than 6 colors
- Use cultural conventions e.g. anger = danger
- Beware of bad interactions (red/blue etc.)
There are 3 safe ways to pick your colour scheme in creating a data visualization.
Similar colours (a.k.a. analogous colours)
Analogous colours are any three colors which are side by side, e.g. Cyan, ocean and blue. For example, blue is the colour of the bar charts, cyan to highlight something important and ocean for everything else in between.
Opposite colours (a.k.a. complementary colours)
These are colours at two opposite ends, e.g. magenta and green (which can also be found in real life scenarios with flowers and leaf). These opposing colors create maximum contrast and maximum stability.
Always stick with social conventions and never use too much of a certain colour e.g. red for danger without very good reason. To demonstrate the smaller scale of things, a different hue paired with lightness is generally recommended as compared to changing colours entirely.