What you can actually change about app colors
Most apps don't let you change their colors directly. Instead, you're changing the system theme — the dark or light mode that your phone or computer uses — and some apps will follow that setting automatically. A few apps, like Gmail or Slack, have their own color settings buried in their preferences. Others, like Instagram or TikTok, don't offer any color customization at all.
The confusion happens because "changing app colors" usually means one of three things: switching your phone to dark mode (which makes apps darker), adjusting an individual app's theme settings if it has them, or using accessibility features to change how colors appear on your screen. Each one works differently depending on what device you're using.
Key Takeaways
- Dark mode and light mode are system-wide settings that affect many apps at once, but not all apps will respond to them.
- Some apps like Gmail, Slack, and Discord have their own color or theme menus in Settings that override your system choice.
- If an app doesn't offer theme options, you cannot change its colors — the app designer decided not to include that feature.
- Accessibility features like color filters or high contrast mode can change how all colors appear on your screen, but they affect everything you see.
Switching to dark mode or light mode on iPhone
On iPhone, go to Settings, then Display & Brightness. You'll see three options: Light, Dark, and Automatic. Choose Dark to make your phone dark, or Light to keep it bright. If you pick Automatic, your phone will switch to dark mode at sunset and back to light mode at sunrise.
Not every app will turn dark when you do this. Apple's own apps like Mail, Messages, and Safari will respond. Many third-party apps will too, but some ignore the system setting entirely. If an app stays bright even after you've switched to dark mode, that app's developer chose not to support dark mode.
If a specific app has its own theme settings, those will override your system choice. For example, if you turn on dark mode system-wide but then open Twitter and go to Settings > Display and Appearance and choose Light, Twitter will stay light even though your phone is set to dark.
Switching to dark mode or light mode on Android
On Android, the steps vary slightly depending on your phone's manufacturer. On most phones, swipe down from the top twice to open Quick Settings, then look for Dark theme or Dark mode and tap it. On some Samsung phones, you'll find it under Settings > Display > Dark mode.
Like iPhone, Android apps don't all respond to this setting. Google's apps like Gmail, Maps, and YouTube usually do. Many other apps will too, but some won't. If you want to check whether an app supports dark mode before you switch, open the app and look in its Settings — if there's no theme or appearance option, it probably doesn't support dark mode.
Some Android phones also let you schedule dark mode. On Samsung phones, go to Settings > Display > Dark mode and tap Scheduled, then choose a time. Your phone will automatically switch at that time each day.
Finding color settings inside individual apps
Apps that do offer their own color controls usually hide them in Settings. Open the app, look for a menu icon (three horizontal lines, three dots, or a gear icon), and tap Settings or Preferences. Then look for tabs or sections called Theme, Appearance, Display, or Colors.
Gmail lets you choose between Light, Dark, and System Default. Slack has Light, Dark, and Auto options. Discord offers Light, Dark, and a few other themes. Twitter (now X) has Light, Dark, Dim, and Lights Out. But Instagram, TikTok, Snapchat, and many other apps don't have this menu at all — they use whatever your phone's system setting is, and that's your only choice.
If you've looked through an app's entire Settings menu and found no theme or appearance option, the app doesn't support color customization. You can't add that feature yourself.
Using accessibility color filters on your device
If you want to change how colors appear across your entire screen — not just switch between dark and light — you can use accessibility features. These are designed for people with color blindness or light sensitivity, but anyone can use them.
On iPhone, go to Settings > Accessibility > Display & Text Size, then scroll down to Color Filters. Turn it on and choose from Grayscale, Red/Green Filter, Blue/Yellow Filter, or Grayscale. You can adjust the intensity with a slider. This will change the colors of every app on your screen, not just one.
On Android, go to Settings > Accessibility > Display, then look for Color Correction or Color Adjustment (the exact name varies by phone). You can choose from Deuteranomaly, Protanomaly, Tritanomaly, or Monochromacy. Like iPhone, this affects everything you see.
Changing app colors on Windows and Mac
On Windows, right-click your desktop and choose Personalize, then go to Colors. You can choose Dark or Light mode, or let Windows decide based on the time of day. This affects Windows itself and many apps, but not all. Some apps like Chrome, Firefox, and Spotify have their own theme settings that override your system choice.
On Mac, go to System Settings > Appearance and choose Light, Dark, or Auto. Like Windows, this affects macOS and many apps, but not all. Some apps ignore this setting. If you want to change colors in a specific app, open the app and look in its Preferences or Settings menu — the location varies by app.
If an app on your computer doesn't have a theme option and doesn't respond to your system setting, you cannot change its colors. Browser extensions exist that claim to force dark mode on websites, but they're unreliable and can break how websites look.
What to do if an app won't change colors
If you've switched your phone or computer to dark mode and an app is still bright, or vice versa, you have two options: check the app's own settings, or accept that the app doesn't support color customization.
First, open the app and look for Settings, Preferences, or a menu icon. Search for Theme, Appearance, Display, or Colors. If you find an option, use it. If you don't find anything after checking the entire Settings menu, the app's developer didn't build that feature in. You cannot add it yourself, and no setting on your device will force the app to change.
If the app is important to you and you'd like it to support dark mode, you can contact the developer through the app's support page or social media and request the feature. Developers do listen to these requests, especially if many people ask.
Frequently Asked Questions
Will dark mode drain my phone battery less?
On phones with OLED screens (most newer iPhones and high-end Android phones), dark mode uses slightly less battery because black pixels use less power than white ones. On phones with LCD screens, dark mode makes almost no difference. The battery savings from dark mode are usually small — a few percent at most.
Can I make one app dark while keeping others light?
Not automatically. If you set your phone to dark mode, most apps will turn dark. If an app has its own theme setting, you can override the system choice for just that app. But you cannot make your phone light overall and then force one specific app to be dark.
Why do some apps ignore dark mode?
The app's developer chose not to build dark mode support. This is usually because they didn't think it was important, or because their app is old and hasn't been updated in years. You can request the feature from the developer, but you cannot force it yourself.
Do color filters work the same way on all phones?
The feature exists on both iPhone and Android, but the names and options are different. iPhone calls it Color Filters, while Android calls it Color Correction or Color Adjustment. The effect is similar, but you'll see different filter options depending on your phone.
Can I schedule dark mode to turn on at a specific time?
Yes, on both iPhone and Android. On iPhone, set it to Automatic in Display & Brightness Settings. On Android, the option is usually in Display settings under Dark mode or Theme, but the exact location depends on your phone's manufacturer. Some phones call it Scheduled or Automatic.