WordPress gives you plenty of ways to change how your website looks, but the right method depends on the theme you are using.
A block theme may let you change site-wide styles, templates, headers and footers through the Site Editor. A classic theme may use the Customizer, its own settings panel or a combination of different tools. A page builder can add another editing layer again.
That is why the first step is not changing colours or adding CSS. It is working out which part of WordPress actually controls the element you want to change.
This guide explains the main routes for customising a WordPress theme, when to use them, and how to avoid making changes that are difficult to maintain later.
Start by Identifying How Your Theme Is Edited
WordPress themes do not all provide the same customisation controls.
Before changing anything, check what kind of theme and editing setup your website uses.
You may be working with:
- A block theme using the Site Editor
- A classic theme using the Customizer
- A classic theme with its own settings panel
- A theme designed around a page builder
- A site using a child theme
- A combination of several of these
This matters because instructions written for one setup may make little sense on another.
For example, if your website uses a block theme, you may find site-wide design controls under Appearance > Editor.
With a classic theme, you may instead find options under Appearance > Customize, provided the theme supports the Customizer.
Some commercial themes add their own menu or settings screens instead.
If you are unsure which route applies, look at the options available under Appearance in your WordPress dashboard and check the documentation for your active theme.
Customising a Block Theme With the Site Editor
Block themes let you use WordPress blocks for more than page and post content.
Through the Site Editor, you can work on parts of the website such as:
- Headers
- Footers
- Navigation
- Templates
- Template parts
- Site-wide colours
- Typography
- Layouts
- Other global styles
You will usually find the Site Editor under:
Appearance > Editor
The available options can vary depending on your WordPress version and active theme.
Use Styles for site-wide design changes
The Styles area lets you change the appearance of the website without editing individual pages one at a time.
Depending on the theme, you may be able to adjust:
- Fonts
- Font sizes
- Colours
- Backgrounds
- Spacing
- Layout widths
- Block appearance
These settings are useful when you want a design change to apply consistently across the website.
For example, changing your site’s main text colour through Styles is generally more manageable than changing individual paragraphs throughout dozens of pages.
Edit templates carefully
The Site Editor can also be used to edit templates that control how groups of pages are displayed.
You might have templates for:
- Pages
- Blog posts
- Archive pages
- Search results
- The homepage
- 404 pages
Changes made to a template can affect every piece of content that uses it.
That makes templates powerful, but it also means you should understand the scope of a change before publishing it.
For a more detailed walkthrough of the Site Editor, see our guide to full-site editing in WordPress.
Customising a Classic Theme
Classic themes use the traditional WordPress theme structure.
Many provide design controls through the WordPress Customizer, although the available options depend entirely on the theme.
You may find the Customizer under:
Appearance > Customize
If that option is not available, your theme may use a different customisation system.
A classic theme might provide controls for:
- Site identity
- Logo
- Colours
- Typography
- Header layout
- Footer layout
- Menus
- Widgets
- Backgrounds
- Blog layouts
- Sidebars
- Additional CSS
Another theme might provide only a few of these.
Do not assume that a setting described in a tutorial will exist on your own website.
Check Your Theme’s Own Settings
Some themes provide their own configuration panel in addition to, or instead of, the standard WordPress tools.
This is particularly common with commercial themes and larger theme frameworks.
You might find settings for:
- Header styles
- Footer columns
- Fonts
- Button styles
- Blog layouts
- Page widths
- WooCommerce layouts
- Mobile behaviour
- Built-in design presets
Where possible, use your theme’s intended controls before reaching for custom code.
Built-in settings are usually easier to understand later and may be less likely to conflict with future theme updates.
The aim should not be to use every option a theme provides. It should be to make the smallest number of changes needed to achieve the design you want.
Make Common Design Changes Through the Simplest Route
Many theme customisations do not require code.
Colours
Use your theme’s global colour controls where possible.
This makes it easier to maintain consistency across:
- Backgrounds
- Headings
- Body text
- Links
- Buttons
- Borders
- Accent elements
Changing colours globally is usually preferable to applying separate colour settings to individual pages and blocks.
Typography
Typography controls may let you adjust:
- Font families
- Font sizes
- Font weights
- Line height
- Heading styles
- Letter spacing
Keep readability in mind rather than treating typography purely as decoration.
The design should still work on smaller screens and at different zoom levels.
Logo and site identity
Your logo, site title and site icon may be controlled through the Site Editor, Customizer or theme settings.
Wherever they are managed, check the result at different screen sizes.
A logo that fits comfortably on desktop can cause problems in a narrow mobile header.
Headers and footers
Block themes may let you edit headers and footers as template parts.
Classic themes may offer predefined layouts or controls through the Customizer or their own settings.
If you need to make major structural changes, understand whether you are editing:
- A global template
- A reusable template part
- A theme option
- A page-builder layout
- Custom theme code
That distinction affects how widely the change will apply.
Navigation
Navigation is another area where the editing route depends on the theme.
Block themes can manage navigation through blocks and the Site Editor, while classic themes may use the traditional menu system.
If you specifically need to create or reorganise a dropdown menu, see our guide to creating a WordPress dropdown menu without code.
Changing Your Homepage
WordPress can either display your latest posts on the homepage or use a page you choose.
You can check this under:
Settings > Reading
If you select a static page as the homepage, you can then edit that page using whichever content editor or builder your website uses.
That might be:
- The WordPress Block Editor
- A page builder
- A theme-specific editor
- A custom template
Changing the homepage setting itself does not determine the design of the page. It simply tells WordPress which content should appear at the main website address.
If your homepage is controlled by a template rather than an ordinary page, you may need to edit that template through the Site Editor or your theme’s own system instead.
Where Page Builders Fit
Page builders such as Elementor, Divi and similar tools can add another design layer on top of WordPress.
They may control parts of an individual page, complete page layouts, or even site-wide elements depending on the builder and configuration.
This can make it less obvious whether a particular design element belongs to:
- The theme
- WordPress itself
- The page builder
- A plugin
- Custom CSS
Before making a change, identify which system created the element.
For example, changing a button style in the theme may have no effect on a button created and styled entirely by a page builder.
If your site relies heavily on a builder, our guide to WordPress page builders provides more context.
Use Custom CSS for Targeted Visual Changes
Sometimes the built-in controls will not give you the exact design you need.
CSS can be useful for targeted visual changes such as:
- Adjusting spacing
- Changing colours
- Modifying font sizes
- Altering borders
- Tweaking alignment
- Changing responsive behaviour
- Styling a particular element
Where you add CSS depends on your setup.
Classic themes may provide an Additional CSS area through the Customizer.
Block-theme setups can provide CSS controls through the modern Styles interface, while some themes or plugins provide their own CSS fields.
Keep CSS changes focused
Custom CSS is most useful when it solves a specific visual problem.
If you find yourself writing large amounts of CSS simply to force the theme into a completely different design, that can be a sign that the underlying theme is not a good fit.
Large collections of overrides can become difficult to understand and maintain, especially when the theme changes its HTML structure or class names in a future update.
Do Not Edit the Parent Theme Directly
It can be tempting to open a theme file and make the change directly.
For a maintained parent theme, that is usually a poor long-term approach.
When the theme is updated, modified files can be replaced by the new versions supplied by the developer.
That can cause your changes to disappear.
For small visual adjustments, built-in controls or carefully managed custom CSS may be enough.
For code-level theme modifications, a child theme may be more appropriate.
Use a Child Theme for Code-Level Theme Changes
A child theme inherits from another theme, known as the parent theme.
It lets you introduce your own theme files or customisations without directly altering the parent theme.
This can be useful when you need to change things such as:
- Templates
- Template parts
- Theme PHP
- Theme-specific functions
- More extensive CSS or styling
- Other files supplied by the parent theme
The exact way a child theme works depends on the parent theme and whether you are working with a classic or block theme.
For that reason, avoid copying generic child-theme code from an old tutorial and assuming it applies universally.
Check the current documentation for the parent theme and WordPress before creating one.
A child theme does not make every change maintenance-free
A child theme protects your own files from simply being overwritten when the parent theme is updated.
It does not guarantee that your customisations will remain compatible forever.
If a parent theme changes its templates, markup, functions or behaviour, a heavily customised child theme may also need updating.
The more code you override, the more maintenance responsibility you take on.
Our guide to updating a WordPress theme safely covers the precautions worth taking when maintaining a customised theme.
Keep Site Functionality Separate From Theme Design
A theme should mainly control how the website is presented.
Be cautious about adding important site functionality directly to theme files.
For example, functionality that should still exist after changing the site’s design is usually better kept separate from the theme.
That could include:
- Important business logic
- Integrations
- Custom content functionality
- Forms
- Tracking
- Site-wide operational features
If changing your theme would unexpectedly remove something the website depends on, the functionality may be too tightly coupled to the design.
Keeping presentation and persistent functionality separate makes future theme changes easier.
Test Theme Customisations Before Publishing Them
A change that looks fine on one page can cause problems elsewhere.
After making theme changes, check representative parts of the website.
Include:
- The homepage
- Standard pages
- Blog posts
- Archive pages
- Search results
- Navigation
- Forms
- Headers and footers
- WooCommerce or specialist plugin pages, where applicable
Also check more than one screen size.
Look for:
- Text wrapping incorrectly
- Overlapping elements
- Menus becoming difficult to use
- Images overflowing their containers
- Buttons becoming too small
- Unexpected spacing
- Colour contrast problems
- Layouts breaking on mobile
For substantial changes involving templates, PHP or multiple site-wide components, a staging site is safer than experimenting directly on an important live website.
Know When the Theme Is Fighting You
Customising a theme is useful when the theme is already reasonably close to what you need.
There comes a point where continued customisation stops being the sensible option.
Warning signs include:
- Large amounts of CSS overriding the original design
- Multiple template files being replaced
- Repeated workarounds for basic layout requirements
- Important plugins looking wrong without extensive fixes
- Updates regularly breaking customisations
- Features being added simply because the theme does not support the required layout
- Difficulty explaining which part of the site controls each design element
At that point, choosing a theme that better matches your requirements may be easier to maintain than continually rebuilding the current one.
If you are considering changing themes, see our guide to choosing the right WordPress theme for your website.
Customise Your Theme With Future Maintenance in Mind
There is no single WordPress theme customisation screen that applies to every website.
The safest approach is to work from the simplest appropriate level:
- Identify whether you are using a block theme, classic theme, page builder or another setup.
- Use the theme’s built-in controls where they provide what you need.
- Use the Site Editor for block-theme site-wide design and template changes.
- Use the Customizer or theme settings where a classic theme provides them.
- Use targeted CSS when the normal controls stop short.
- Use a child theme when genuine code-level theme changes are required.
- Keep important functionality separate from the theme where possible.
- Test significant changes before publishing them.
That gives you a better chance of ending up with a website that looks the way you want without creating unnecessary problems for future updates and maintenance.
If you know what you want changed but your theme does not provide a straightforward way to do it, you can ask Newt Labs about one-off WordPress support.
