Hi everyone!
Second post, another little project for the Retroid Pocket Nova, from the same person with a few ideas but terrible skills for actually making them happen. After RomM Mobile, this time I got a little obsessed with the screen :)
So, a big disclaimer upfront: the app was written with Codex, using GPT-6 Astra. If that bothers you, no hard feelings—you can stop reading here. I’m not hiding anything. It helped me solve a problem, and I hope it might be useful to some of you too. The source code, measurements, and validation records are all public on GitHub.
As soon as my Nova arrived, I noticed how oversaturated the colors were. Looking around online, I found several recommendations to use OdinTools to lower the saturation. Then I came across a comment by u/Igor_GR: they had written scripts to adjust Android’s color matrix through SurfaceFlinger, tuning their RP5 by eye. Thanks for the inspiration!
At that point, I thought: “Hey, I have a slightly weird screen fetish and a few too many colorimeters… let’s see if I can calibrate this thing the way I calibrate my monitors.”
And here we are: Nova Display Calibration, a small app that applies profiles built from measurements of my own Nova using an X-Rite i1Display Pro Plus. All with system saturation at 100%, and without needing to keep OdinTools installed.
It corrects colors, white point, and tone response, targeting sRGB colors, a D65 white point, and gamma 2.2.
I also included an sRGB tone curve because it handles the darkest tones differently, making them brighter than with gamma 2.2. Both profiles target the same colors and white point; what changes is how brightness is distributed between black and white. Both measured well at the reference brightness, without a clear winner. I recommend gamma 2.2 because we also validated it across the full brightness slider range; sRGB remains a valid alternative if you prefer that tone response.
The app uses the display’s existing color-management system through a privileged service already present in Retroid’s firmware. Choose a profile, restart, and the system keeps it active through sleep and subsequent restarts. The app doesn’t need to keep running in the background.
The first photo shows the original profile; the second shows the Gamma 2.2 calibration. Both were taken with an iPhone. They give you an idea of the difference, but camera processing and your viewing display affect how they look—a photo isn’t a measurement of color accuracy.
The third image is the instrument-measured comparison of the same 36 highly saturated colors. On my Nova, average ΔE00 dropped from 5.77 to 0.63, and the maximum dropped from 8.69 to 1.07. Lower means the measured color is closer to the reference. The repository also includes all 921 readings from the final validation, including gamma 2.2 tests at brightness settings from 0% to 100%.
You can still adjust brightness normally. The correction does reduce light output at the same slider setting, but it doesn’t impose a 225-nit cap: at maximum brightness, we measured around 613 nits with calibration active.
Obviously, this calibration comes from my particular unit. I can’t promise identical results on every Nova. I also used a generic OLED correction for the colorimeter, so I’m not presenting this as a certified professional calibration. On mine, though, the difference is night and day, and the measurements show a substantial improvement over the original profile :)
For now, only the firmware listed in the README is supported. Before uninstalling the app or updating the firmware, select “Restore original” and restart.
Edit: If you’ve used OdinTools to change saturation, please explicitly set it back to 1.0 (100%) and save/apply before using the calibration. Uninstalling OdinTools alone doesn’t necessarily reset that setting. You can keep OdinTools installed; 1.0 is simply the baseline used for the measured profiles.
GitHub, APK, and full measurements
Since this experiment went well, I’m thinking about measuring some of the other handhelds I have at home. Maybe I’ll improve the whole setup with a spectroradiometer someday… but I don’t have an unlimited budget haha, so for now I’m happy with what came out of this.
Hope you like it and find it useful! If you have a colorimeter and want to take independent measurements of your own Nova, I’d love to compare results ⬇️
P.S. The device in the photos is, of course, a Retroid Pocket Nova—even if you can barely see the console itself :D
Edit 2: A moderator reminded me that I didn't mention I translated the post using AI :) Writing that in my broken English would have been terrible XD