Set Up Fixed Dialing Numbers (FDN)
If your Oppo phone dials out to numbers you did not approve, or a shared device keeps calling premium lines by mistake, Fixed Dialing Numbers can lock outgoing calls to an approved list. Incoming calls stay unrestricted, only outgoing numbers get filtered. The feature sits behind PIN2, which is easy to overlook in the carrier settings menu.
Answer an Incoming Call
If a call pops up on your Oppo and tapping the screen does nothing, you are probably looking for the wrong gesture. Oppo phones show incoming calls as a full-screen alert rather than a simple tap-to-answer button, which confuses anyone switching from a different Android brand.
Turn Screenshot Gestures On or Off
If a screenshot pops up every time you swipe down with three fingers, or a partial capture opens whenever you touch and hold with three fingers, the screenshot gesture settings on your Oppo phone are active. These gestures work independently from the button combination and are enabled by default in ColorOS. Random captures while gaming or scrolling usually point to one of these gestures firing by accident.
View Messages Stored on SIM Card
Old text messages that arrived before you switched phones often sit only on the SIM card, not in the main inbox of the messaging app. On Coloros this SIM storage is hidden by default, so those messages look like they vanished. A separate settings menu on Oppo phones brings them back into view.
Manage App Permissions
Oppo apps often ask for access to storage, location, or contacts right after installation, and the request rarely explains why the permission is needed. Granting everything by default can let apps read data they never use for their actual function. ColorOS lets you review and change each permission per app at any time, without reinstalling anything.
Show or Hide Notification Icons in Status Bar
On Oppo phones, every app pushes its own icon into the status bar, which quickly turns the top of your screen into a cluttered icon row. If you only want to see how many unread notifications you have, or nothing at all, the icon display is controlled through a separate notification setting. This setting changes how icons appear, not whether you actually receive notifications.
Set Default App Storage to SD Card
Running out of internal storage on your Oppo phone while the SD card sits mostly empty? You cannot install apps directly onto the memory card, but many apps let you redirect new data to it once you set the card as the default storage target. Whether this actually frees up space depends on whether the app itself supports external storage.
Change App Icon Style
If every app icon on your Oppo still shows the same rounded-square outline, the built-in icon shape picker probably has not been touched yet. Coloros lets you switch all home screen icons at once between styles like standard, material, pebble, or a custom outline. The setting is easy to miss because it sits inside general appearance options rather than the home screen settings themselves.
Import Contacts from a vCard File
Switching to an Oppo phone often means your old contacts sit in a vCard file or on another device, and there is no simple sync button for that. Coloros only lets you import a full .vcf file or pull contacts directly from another phone via Bluetooth, without any option to pick single entries from the list. If you only need a handful of numbers, you end up with everything from the source file instead.
Show or Hide Password Characters While Typing
On Oppo phones, the last character you type into a password field briefly shows up on screen instead of staying hidden behind dots. That's handy for spotting typos, but it can expose your password if someone else is looking at your screen. Whether this happens depends on a single toggle buried in your security settings.
Turn Grid Lines On or Off in Camera
Framing a landscape shot without a horizon reference makes tilted photos easy to miss. On many Oppo phones the camera grid overlay is switched off by default, so there is no composition guide in the viewfinder until you turn it on. Photo and video mode also handle this setting separately, which causes confusion when the grid shows up in one mode but not the other.
Set Up a Proxy Server for Wi-Fi
If you want to browse without exposing the real IP address of your Oppo phone, a proxy server routes your traffic through a different address. Without one set up, every app and website still sees your actual connection details. A proxy only works once you are already connected to a Wi-Fi network.
Unarchive a Conversation in Messages
If a chat suddenly disappears from the Messages home screen on your Oppo phone, it usually was not deleted but moved to the archive. Archived conversations stay hidden until you pull them back manually, so incoming texts from that contact can go unnoticed. This mostly happens after swiping a chat away or tidying up the inbox.
Change Camera Storage Location
If new photos on your Oppo phone keep filling up internal storage even though a memory card is inserted, the camera app is likely still set to save shots to the device only. This becomes a problem once internal storage runs low and you cannot move existing photos automatically. Switching the preferred save target inside the camera settings fixes this without touching your gallery app.
Move Apps and Files to an SD Card
When internal storage on your Oppo phone runs low, photos, videos, and even some apps stay stuck on the device even though an SD card is installed. Coloros includes a built-in transfer tool, but it only works with certain file types and not every app is eligible for the move. Knowing which data can actually shift to the memory card helps you free up space without deleting anything you need.
Custom Ringtone for a Contact
If your Oppo phone plays the same generic ringtone no matter who calls, you can't tell an important contact from a random number without looking at the screen. ColorOS lets you swap in a custom sound for individual contacts instead of relying on the default tone. This works with your own audio files, not just the built-in ringtone list, and it stays independent from Focus or Do Not Disturb rules.
Set Up Face Recognition Unlock
If Face unlock is missing from your Oppo lock screen options, it usually means no unlock password has been set yet. ColorOS requires a password or PIN as backup before it lets you register your face for the screen lock, app lock, or private safe. Without that step, the Add face option stays hidden or greyed out.
Set Data Usage Billing Cycle Start Date
If your Oppo phone always resets data usage tracking on the 1st of the month, but your carrier bills you on a different day, the numbers in your data usage stats never match your invoice. This mismatch comes from the mobile data limit settings, where the tracking start date is fixed by default. You can align it with your actual billing date instead.
Change Media Volume
If videos, games or music play louder or quieter than expected on your Oppo phone, the media volume slider is usually the cause, not the ringtone or notification volume. This level controls audio for apps and their content separately from calls and alerts. On some ColorOS versions the volume buttons only adjust it while media is actively playing.
Access Scientific Calculator Functions
If the Calculator app on your Oppo phone only shows basic addition and multiplication, functions like sine, cosine and tangent seem to be missing entirely. Many users assume Coloros ships without a scientific mode, when it is actually built into the same app and just hidden from view. This becomes a problem the moment you need quick trigonometry or advanced math on the go.
Show or Hide Holidays in Calendar
If your Oppo calendar is suddenly full of public holidays you never asked for, or they vanished and you want them back, the built-in Google calendar sync is the reason. The holiday data comes straight from the region set in your Google account, not from a manual list you control. A single toggle in the calendar menu decides whether these entries show up at all.
Turn VoLTE Calls On or Off
If your Oppo phone keeps falling back to a 2G or 3G connection for calls, call setup takes longer and voice quality suffers. This happens because VoLTE is switched off or was reset after a system update, so the phone dials over the older mobile network instead of your 4G data connection. Carrier support and a valid data plan both play a role here.
Reset Camera Settings to Default
If your Oppo camera app looks off after tweaking resolution, grid lines, watermark or video quality, tracking down every changed option one by one gets tedious fast. Filters, saved modes and exposure tweaks can pile up until the app behaves unpredictably. ColorOS includes a single function that reverts every camera option at once instead of making you undo each change manually.
Change Alarm Volume
On Oppo phones running ColorOS, the alarm volume is one shared setting for all alarms, not something you adjust per individual alarm. If one alarm feels too quiet or too loud, you cannot fix it in isolation without affecting every other alarm you have set.