docs(manifest): Improve theme_color member page (#35643)

* improve page

* apply formatting

* formatting

* fix values formatting

* fix code alignment

* fix review comments

* Apply suggestions from code review

* Update files/en-us/web/manifest/theme_color/index.md

files/en-us/web/manifest/theme_color/index.md

@@ -7,27 +7,110 @@ browser-compat: html.manifest.theme_color
 
 {{QuickLinksWithSubpages("/en-US/docs/Web/Manifest")}}
 
-<table class="properties">
-  <tbody>
-    <tr>
-      <th scope="row">Type</th>
-      <td><code>String</code></td>
-    </tr>
-  </tbody>
-</table>
+The `theme_color` member specifies the default color for your web application's user interface.
+This color may be applied to various browser UI elements, such as the toolbar, address bar, and status bar.
+It can be particularly noticeable in contexts like the task switcher or when the app is added to the home screen.
 
-The `theme_color` member is a string that defines the default theme color for the application. This sometimes affects how the OS displays the site (e.g., on Android's task switcher, the theme color surrounds the site).
+This color application can provide a more native app-like experience for your web app, especially when it's loaded in [standalone](/en-US/docs/Web/Manifest/display#standalone) mode.
+
+## Syntax
+
+```json
+"theme_color": "<color-value>"
+```
+
+### Values
+
+- `<color-value>`
+
+  - : A string that specifies a [valid color value](/en-US/docs/Web/CSS/color_value).
+
+    > [!NOTE]
+    > Browsers may ignore the alpha component of the color based on the context.
+    > In most environments, `theme_color` cannot be transparent.
+    > It's recommended to use fully opaque colors (alpha value of 1 or 100%) to ensure consistent behavior across different platforms and browsers.
+
+## Description
+
+While optional, specifying a `theme_color` allows you to extend your app's visual identity beyond its content areas.
+Choose a `theme_color` that aligns with your app's brand guidelines, as this can enhance user recognition and recall, particularly when your app is viewed alongside other applications or system interfaces.
+
+In browsers that support `theme_color`, the value specified in the manifest file serves as the default theme color for your web app across all pages where the manifest is applied.
+You can override this default in the following ways:
+
+- Using the [`theme-color`](/en-US/docs/Web/HTML/Element/meta/name/theme-color) value of the `name` attribute in the HTML `<meta>` element: You can specify a theme color for a web page that's different from the manifest `theme_color` specified for your app. This enables you to set different theme colors for individual pages within your app.
+
+  ```html
+  <meta name="theme-color" content="#9370DB" />
+  ```
+
+- Combining the `<meta name="theme-color">` element with media queries: You can specify the theme color to be used based on user's color scheme preference.
+
+  ```html
+  <meta
+    name="theme-color"
+    content="#F4E6D8"
+    media="(prefers-color-scheme: light)" />
+  <meta
+    name="theme-color"
+    content="#5D4037"
+    media="(prefers-color-scheme: dark)" />
+  ```
+
+These override methods provide you the flexibility to adapt your app's appearance for specific pages or user preferences, improving the overall user experience.
+
+Browsers may also adjust the applied theme color based on user preferences.
+If a user has set a preference for light or dark mode, browsers may override the manifest `theme_color` value to support any [`prefers-color-scheme`](/en-US/docs/Web/CSS/@media/prefers-color-scheme) media query defined in your app's CSS.
+
+```css
+body {
+  background: #f8f9fa;
+  color: #212529;
+}
+
+@media (prefers-color-scheme: dark) {
+  body {
+    background: #212529;
+    color: #f8f9fa;
+  }
+}
+```
 
 ## Examples
 
+### Using a named color
+
 ```json
 "theme_color": "red"
 ```
 
+### Using an RGB value
+
+```json
+"theme_color": "rgb(66, 133, 244)"
+```
+
+### Using a hexadecimal value
+
+```json
+{
+  "name": "My First App",
+  "display": "standalone",
+  "background_color": "#ffffff",
+  "theme_color": "#ff4500"
+}
+```
+
 ## Specifications
 
 {{Specifications}}
 
 ## Browser compatibility
 
 {{Compat}}
+
+## See also
+
+- [`display`](/en-US/docs/Web/Manifest/display) manifest member
+- [`background_color`](/en-US/docs/Web/Manifest/background_color) manifest member
+- [`scope`](/en-US/docs/Web/Manifest/scope) manifest member