CF.lumen

In-app purchases
4.0
5.15K reviews
100K+
Downloads
Content rating
Everyone
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About this app

CF.lumen adapts the colors on your Android device based on the position of the sun, or your custom configuration.

NOTE: Android 5.0 is now required. Versions up to v3.16 that support 4.4 KitKat are still available from the XDA thread (see far below). Performance drop since v3.60? Turn on performance mode.

When using the default settings, your display will get a warmer tint (lower color temperature) when the sun is down, vastly reducing strain on the eyes. Blue light makes your brain want to stay awake, and a lower color temperatures reduces the amount of blue displayed; using this in the evening reduces your brain's effort to keep you awake at night.

During sleeping hours by default a red filter is used. Red strains your eyes the least, and retains your night vision.

Light sensor

The light sensor can be used to automagically adjust the color: switch to the sleep filter in full dark, or to the day filter (usually none) under bright lights.

Because light sensor quality varies wildly between devices, a calibration option is provided to experiment with.

Color filters

Several filters are provided. Those named after a color (red, green, blue, ...) do not limit the display to those colors, but convert the displayed image to grayscale first, then display that image in levels of the selected color. This preserves details that would otherwise be lost.

Grayscale, invert colors, temperature adjustment and custom R/G/B adjustment filters are also provided.

Colorblindness

The master color filter setting also has an option for colorblindness enhancement, with settings for protanopia/anomaly, deuteranopia/anomaly and tritanopia/anomaly. These options in theory enhance clarity and color detail.

No claims are made to the effectiveness of these filters. These filters were thought up by Google engineers, CF.lumen just includes them.

Pro version

Upgrading to CF.lumen Pro will support my developments, remove all nags, unlock the option to start at device boot (make sure you test your configuration first), and unlocks notification options. It also enables Tasker integration.

In Pro mode, the notification adds convenient buttons to quickly disable the current filter or switch to sleep mode, and you can switch the notification to when enabled mode, which shows the notification only when a color filter is active.

In non-Pro mode, the notification only asks you to upgrade to Pro. It may seem that notification is just there to annoy you, but it actually prevents Android from randomly killing the background service taking care of all the work. Getting rid of it without getting the service killed can be done by going to Settings -> Apps -> CF.lumen and unticking Show notifications.

Having Chainfire3D Pro (ancient) installed will enable Pro.

Performance

When no color filter is active, there should not be any noticeable performance impact. When a filter is active, impact depends on device and what you are doing. On some devices we have tested there was no performance impact at all, on others it was slightly noticeable. It also depends on the driver in use.

Future

Keep in mind that Android's rendering system changes over time. You should be aware that this app may simply stop working on future Android versions without the possibility of a fix.

Scary permissions

By far most permissions are used only for Google Maps to set your location, and Google Play to provide for In-App Purchases. I cannot make any claims as to what information the Google components do or do not send to Google servers, but no information is sent to me or anyone else (than Google).

More

Advanced user more information, discussion, and support, can be found in this app's thread on XDA-Developers: http://forum.xda-developers.com/showthread.php?p=51779367
Updated on
Dec 22, 2020

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
Learn more about how developers declare sharing
No data collected
Learn more about how developers declare collection

Ratings and reviews

4.1
4.84K reviews
A Google user
February 11, 2020
Does what it does very well, possibly the best of ifs kind on any os? Idk, definitely the best I've tried on mobile. But it doesn't control brightness? Maybe it just controls that exactly the same way the stock tools do, and relying on a separate app for that has made me forget where it is in lumen. I'm not certain it's missing. But it should be present & it should allow brightness to be set below the normal Android min (and maybe also above max, if safe). I hope CF returns to the people.
3 people found this review helpful
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Myriah
December 28, 2020
Since the update, it stopped working on my non-rooted phone. It appears this was planned, I assume because the developer lost access to maintain proper control on non rooted devices. But it has still left me heartbroken as I loved this app. I have chronic migraine and this has been the most helpful app I have ever had to maintain my ability to use my phone with a migraine. Truly a loss for me.
53 people found this review helpful
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Rox K.
September 11, 2021
Update: I now have to disable it for some apps that don't allow apps to draw over screen. I do that, then re-enable. I use v3.7 cuz not rooted. ... I used this app for years, finding it after using f.lux on my computer for MANY years. Get PRO MODE!! This app is GREAT - VERY customizable (or auto), have never had a problem with it turning on. Has daytime/night/sleep modes that are super easy to postpone, turn off (for a short time or...) Can't say enough about this app! Awesome! Highly recommend!
15 people found this review helpful
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What's new

Bare minimum(!) to somewhat support rooted users on Android 11. Rootless and injection driver have been removed as they are currently incompatible.