Color Settings
In various sections of the theme (for example, Rich Text, Image Banner, and Category List), you can select a color scheme from the colors you set in the Theme Settings and apply it to that section. A default color scheme is used for your theme, which can be changed at any time in the Theme Editor. Adding your brand colors will ensure a coherent application of your color palette in your online store.
You can find out more on the official Shopify documentation.