Custom themes
You can create and customize a completely new theme for your site. At the top of the "Themes" tab menu under "Custom," click the "+" button.
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Give your custom theme a name, then click the "Next" button. Make your choices about color and text for your custom theme, but don't worry, you can change these later.
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Now when you click on the themes tab, your custom theme will appear at the top of the menu. You can switch between themes as many times as you want if you change your mind about look at feel.
You can further customize your theme by clicking on the three dots that appear in the upper right corner and selecting "Edit" from the menu that appears.
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Customization categories
The customization categories include colors, text, images, navigation, components, and spacing.
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The colors menu allows you to create 3 colorways within your style. You can give each style a different default background color, text color for titles and headings, and text color for body text.
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The text customization menu allows you to set a default font, size, format, alignment, line spacing, and paragraph spacing for normal text, titles, headings, subheadings, and small text.
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The images menu allows you to set a background for your header, a logo for your site, and a favicon (the icon that appears in the browser tab beside the name of your site).
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The navigation menu gives you the option of listing your pages along the top of your site, or along the side of your site. There are a lot of different options dealing with how you show your site visitor where in the site you are. Try different variations to see what you like best.
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The components menu allows you to customize the way buttons, dividers, links, and the image carousel appear in each of the 3 styles of your custom theme.
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The spacing menu deals with site density and width. From Google's documentation regarding spacing:
- Default: Recommended for sites that have less content and will appear spread out
- Full: Recommended for sites that have more content and will appear densely packed
- Wide: Recommended for sites that fall between default and full
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Check out Google Support's How to use Google Sites and Redesign your Google sites articles for more information.