Pure & Simple gives you the ability to customize almost every colour within this theme. There may be some elements that you need to create custom CSS to manage the colours of those elements, but for the most part, you should be able to achieve unlimited colour combinations with your website with the built-in colour selectors.
There are many colour options throughout the theme option settings and can be found on different tabs within the customizer. For example, the one in the screenshot below is found on the Navigation tab:
- Go to Appearance >> Customize >> Colours
- Click on any of the colour selectors and choose your colours
- Click on Save and Publish