You can make the theme match your brand by changing logo, colors and fonts. You do this by going to Customizer → Branding.
Choose your default colors here. Note that you can choose to use other colors for specific elements later. For example, the Primary Brand Color will be used as the background color for buttons by default, but if you want to use another color for buttons specifically, then you can change that under Customizer → Branding → Buttons.
After changing these colors, please Publish the changes and reload the page. This will make sure that the color palettes are updated in other places of the customizer.
Primary Brand Color
Used for buttons, badges etc.
Secondary Brand Color
Used as background color for table headers, table footers and some other blocks. This color will be used as a background sometimes, with text appearing on top of it. So make sure it is light enough for text to be visible on top of it.
Choose your main font and heading font here. You can choose from hundreds of Google Fonts. Explore Google Fonts.