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 Data Saving On or Off
If background apps on your Oppo phone suddenly stop syncing or notifications arrive late, Data Saving mode is likely blocking their mobile data access. Even apps you are actively using can load slower or skip previews and thumbnails while the mode is active. This setting sits inside the mobile data menu and is easy to miss when troubleshooting connectivity issues.
Change Ringtone
Stuck with the same default ringtone on your Oppo phone and want something else for calls? Coloros lets you pick from built-in tones, but on dual SIM devices each SIM number can carry its own separate sound. Missing this per-SIM setting is why some calls still ring with the wrong tone even after changing it once.
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.
Turn On TalkBack (Accessibility)
If a single tap on your Oppo now selects text and reads it aloud instead of opening the app, TalkBack is likely running. This screen reader changes how taps, swipes, and double-taps work across the whole system. Turning it on or off correctly keeps accidental activation from locking you out of normal navigation.
Delete an SMS Conversation
Deleting a long text thread message by message on ColorOS wastes time when all you want is the whole conversation gone. A quick long-press on the conversation itself skips the manual cleanup and removes every message in it at once.
Turn Power Saving Mode On or Off
If your Oppo phone suddenly dims the screen, cuts the screen timeout to 15 seconds, and stops apps from syncing in the background, Power saving mode is active. This mode can switch on by itself at low battery or stay on after you enabled it manually, and it often delays notifications and app updates. Switching it off brings back normal brightness and sync behavior right away.
Turn Call Waiting On or Off
If you miss a second incoming call while already on a call on your Oppo phone, the call waiting feature might be turned off. Some carriers switch it on by default, but the toggle sits in the phone's network settings and you can check or change it yourself.
Change Time Zone Manually
If you swap SIM cards or connect to a foreign network, your Oppo phone often jumps to the wrong time zone on its own. Clock apps, alarms and message timestamps can then be off by hours, because Coloros pulls the zone from the current network instead of your actual location.
Turn Gesture to Take Photo (Show Palm) On or Off
If your Oppo camera keeps snapping a shot every time you raise an open hand in front of it, the Gesture to take photo (Show Palm) feature is doing exactly what it was built for. It watches the frame for a palm and fires the shutter automatically, which is handy for hands-free selfies but annoying when a hand passes by accident. Whether you want it running or off depends on how you actually use the camera.
Turn Lens Stain Detection On or Off
If your Oppo camera keeps flashing a dirty lens warning even after you wiped it down, the automatic lens stain detection is misreading brightness patterns near the edge of the frame. This ColorOS check can misfire in low light, with wet fingers, or when a case sits close to the lens ring. Switching the feature on or off changes how often that banner shows up while you shoot.
Turn On/Off Autofill Service
If a form keeps suggesting old addresses, outdated passwords, or the wrong Google account whenever you tap a field, the Autofill service on your Oppo phone is likely still linked to a provider you no longer want active. This often happens after switching Google accounts or installing a password manager that never became the default. Turning the current service off - or picking a different one - is the only way to stop the wrong data from popping up.
Change Home Screen Grid Size
If your Oppo home screen feels cramped with too many icons squeezed into each row, or the tiles look oversized with too few apps per screen, the grid layout is set to a fixed size. Coloros offers several grid options, usually starting with 4x6 and 5x6, and some models add extra layouts. Picking the wrong size can cut off app names or leave large empty gaps between icons.
Lock Screen Sound On/Off
Locking or unlocking your Oppo phone stays silent by default, so you never hear an audible cue that the screen actually locked. If you rely on that click as feedback, the missing tone can make it seem like the lock did not register. The toggle controlling this sits inside the sound and vibration settings, separate from ringtone and notification volume.
Turn Contact Sharing via Bluetooth On or Off
If your contacts don't show up on another device after a Bluetooth pairing, contact sharing is probably switched off for that specific connection. Coloros stores this permission per paired device, so turning it on for one phone or car system does not apply to the next device you connect.
Adjust Screen Brightness (Manual & Automatic)
When the screen stays too dim indoors or turns painfully bright at night, auto-brightness on your Oppo phone is likely misreading the light around you. The quick slider in the notification shade only gives a rough fix, and many owners never open the full display settings where the actual control sits. Switching between automatic and manual mode changes how reliably the screen matches the room.
Change Keyboard Location
If the on-screen keyboard on your Oppo phone sits too close to the bottom edge, reaching the top row with your thumb becomes awkward during one-handed typing. Coloros offers a setting that adds blank space below the keys, shifting the whole keyboard upward. This makes a noticeable difference on larger displays where the default position feels too far down for comfortable use.
Ringtone Volume Settings
If your Oppo phone rings too quietly or too loudly during calls, but notification sounds seem fine, you are likely looking at two separate volume sliders. Ringtone volume and notification volume run on independent controls, so adjusting one does not touch the other. This mix-up leads many users to think their phone volume is broken when it is just set on the wrong slider.
Show or Hide World Clock Widget on Home Screen
Added several cities to the World Clock app but can't get them onto your home screen? On Oppo phones the World Clock only appears as a home screen widget once a specific system toggle is switched on, otherwise the app stays hidden from the widget drawer. If the widget refuses to show up, or you want to remove it without deleting your saved cities, one setting in Date & time decides that.
Set Date and Time Automatically
If your Oppo phone shows the wrong time or date after a SIM swap or a trip abroad, network time sync has likely been switched off. This setting decides whether ColorOS keeps the clock updated from your carrier network or waits for you to enter it manually.
Delete Single or Multiple Contacts
If your contact list on your Oppo phone is cluttered with duplicate entries or people you no longer need to reach, removing them one by one gets tedious fast. The Contacts app lets you select several entries at once and send them to the trash in a single action, but the multi-select toggle is easy to miss if you only tap through individual entries. Knowing where that option sits saves you from repeating the same steps over and over.