Bitrix24 has a tool for changing the design of websites and online stores. The site design settings apply to all blocks on all pages, unless you manually change the block design.
To change the design, choose the site or the online store from the list and click Site design.
Design settings
On the settings page, there is a small block with the text, the header, and the button. You'll see the elements changes when you set the design settings.
The Color theme changes the color of buttons and some other elements like text delimiter, depending on the block.
The color of the text and the headings can be changed in the following blocks:
The font of the text and the headings can be changed in the following blocks:
If you want to change the background of the current page, put tick next to Custom page background and upload the image.