Where to find appearance settings in individual apps
Most iPhone apps store their appearance settings inside the app itself, not in your phone's main Settings. Open the app you want to change, then look for a menu icon — usually three horizontal lines, three dots, or a gear symbol. Tap it, then search for words like "Appearance," "Display," "Theme," or "Settings."
The location varies by app. In some apps like Mail, you'll find appearance controls under Settings > Mail > Display & Text Size. In others like Notes, the option sits in the app's own menu. If you can't find it in the obvious places, try the app's help section or search within the app for "dark mode" or "theme."
Some apps don't offer appearance controls at all — they follow your phone's system-wide setting instead. If an app doesn't have its own appearance menu, it will automatically switch between light and dark based on your iPhone's overall setting.
Key Takeaways
- Most apps have their own appearance settings inside the app menu, not in your iPhone's main Settings.
- Look for a menu icon (three lines, three dots, or gear) within the app to find display or theme options.
- If an app has no appearance menu, it will follow your iPhone's system-wide light or dark mode setting.
- Some apps let you schedule when dark mode turns on and off, separate from your phone's schedule.
- Text size, brightness, and color filters are often grouped with appearance settings in the same menu.
Using your iPhone's system-wide dark mode for all apps
Your iPhone has a master dark mode setting that affects every app on your phone unless that app has overridden it with its own setting. To turn on dark mode for your entire phone, go to Settings > Display & Brightness, then tap "Dark" at the top of the screen.
You can also schedule dark mode to turn on automatically at sunset and off at sunrise. In the same Display & Brightness menu, tap "Automatic," then choose "Sunset to Sunrise" or "Custom Schedule." Custom Schedule lets you pick exact times — for example, 9 p.m. to 7 a.m.
When you turn on dark mode system-wide, most apps will switch to a dark background and light text. Apps that have their own appearance settings may override this — for instance, an app might stay in light mode even though your phone is set to dark. In those cases, you'll need to change the setting inside that specific app.
Changing text size and font across apps
Text size is separate from dark mode but often grouped nearby in your phone's settings. Go to Settings > Display & Brightness > Text Size and drag the slider left to make text smaller or right to make it larger. This affects text in Mail, Messages, Notes, and many other built-in apps.
Some apps also let you change text size from within the app itself. Mail, for example, has a separate text size control in Settings > Mail > Display & Text Size. If you change the system-wide text size and an app still looks too small or too large, check that app's own settings menu.
Font choices are less common on iPhone than text size. Most apps use the system font, which you cannot change. A few apps like Notes let you pick between serif and sans-serif fonts, but this is done inside the app, not in your phone's main Settings.
Adjusting brightness and color filters
If an app looks too bright or too dim, first check your iPhone's overall brightness. Swipe down from the top-right corner of your screen to open Control Center, then drag the brightness slider up or down. This affects your entire phone, not just one app.
For more precise control, go to Settings > Display & Brightness and drag the brightness slider. You can also turn on "True Tone," which adjusts your screen's color temperature based on the light around you. This can make apps easier on your eyes in different lighting conditions.
If you have color blindness or light sensitivity, Settings > Accessibility > Display & Text Size offers color filters and other options. You can enable "Color Filters" and choose from several types, including Grayscale, Red/Green, Blue/Yellow, and others. These affect all apps on your phone.
Changing app icon appearance and home screen layout
You cannot change how an app's icon looks on your home screen — the icon is set by the app developer. However, you can organize your home screen to make apps easier to find. Long-press any app icon, then tap "Edit Home Screen" to move it, delete it, or create folders.
Some apps let you add widgets to your home screen or lock screen, which can change how information from that app appears. Long-press your home screen, tap the plus button, find the app, and select a widget size. Widgets show live information like weather, calendar events, or news without opening the full app.
If you want a different visual style for your entire phone, you can change your wallpaper and lock screen design. Go to Settings > Wallpaper > Add New Wallpaper, then choose a photo or built-in image. This won't change individual app appearances, but it changes the overall look of your phone.
Fixing apps that won't switch to dark mode
If your phone is set to dark mode but an app stays light, the app developer has chosen to ignore your system setting. First, check whether that app has its own appearance menu. Open the app, find the menu, and look for a dark mode or theme option. If one exists, turn it on there.
If the app has no appearance setting and won't switch to dark mode, you have two options: contact the app developer through the app's support or feedback menu, or switch your phone back to light mode. Some older apps were built before dark mode existed and have never been updated to support it.
You can also use a workaround: go to Settings > Accessibility > Display & Text Size and turn on "Increase Contrast" or "Reduce Transparency." These won't make the app dark, but they can reduce eye strain if the app is too bright.
Common mistakes when changing app appearance
The most common mistake is looking for appearance settings in your phone's main Settings instead of inside the app. Remember: most apps control their own look. If you change your phone's dark mode but an app still looks the same, the app has its own setting that overrides your system choice.
Another mistake is confusing text size with zoom. Zooming in on your entire screen (Settings > Display & Brightness > Zoom) makes everything bigger but can cut off content. Text size only affects text in compatible apps and is usually the better choice.
Don't assume all apps support dark mode. Older apps and less common apps may not have this feature. If an app doesn't offer dark mode and you need it, check whether the app has been updated recently — developers sometimes add dark mode in new versions.
Frequently Asked Questions
Can I make dark mode turn on only for certain apps?
No, dark mode is either on or off for your entire phone, or on a schedule. You cannot set it to dark mode for one app and light mode for another. However, individual apps can override your system setting — so if an app has its own dark mode toggle, you can turn it on or off separately from your phone's setting.
Why does my app look different on my friend's iPhone?
Your friend may have a different iPhone model with a different screen size, or they may have changed text size, brightness, or dark mode settings differently than you. Apps also look different depending on which version of iOS you're running — if you haven't updated your phone recently, some apps may look outdated.
Does changing app appearance use more battery?
Dark mode uses slightly less battery on iPhones with OLED screens (iPhone 12 and newer), because dark pixels use less power. On older iPhones with LCD screens, dark mode makes almost no difference to battery life. Text size and brightness changes have minimal battery impact either way.
Can I change the appearance of apps I don't use often?
Yes, you can change appearance settings in any app, whether you use it daily or rarely. Open the app, find its menu, and look for appearance or display options. These settings stay saved even if you don't open the app for weeks.
What if an app crashes when I try to change its appearance?
Close the app completely by swiping up from the bottom of your screen (or swiping down from the top-right on newer iPhones), then open it again. If it keeps crashing, try restarting your iPhone. If the problem continues, delete and reinstall the app from the App Store — this often fixes crashes related to settings.