Use different hues to distinguish categories and How to create a colour scale for an arbitrary main colour by City of London Style Guide from London Style Guide
When you’re creating hues, it makes sense to immediately think about lighter and darker versions of these hues too. You’ll need these shades for less highlighted parts, to emphasize an underlying order, or to distinguish between subcategories. ==When you go darker, try to increase the saturation of your colors. You might even need to shift the hue a little bit to make them work. When you go lighter, consider decreasing the saturation.== Datawrapper