All our themes comes with 5 different color samples (1) that are created by professional designers for the template to be as good as possible. If you want you can use custom colors, you can do this by clicking on the gear (2)
Each color box change something in your template. Normally, changes color box:
The background color of your page.
2. Menu and footer background
3. The Buttons and Links
4. The headings and dividers
5. Paragraphs
6. Text in the navigation menu
7. Wrong Side Rings menu (if any)
Just click on the color box and select a color from the color picker below (8) or enter HEX numbers (9)