Sampled from 3 of nRF Device Firmware Update's App Store screenshots — background, accent and theme, measured by LaunchShots (not something Apple publishes).
#040404 bg
#272727
#04ACCC accent
#FFFFFF text
The nRF5x Series chips are flash-based SoCs, and as such they represent the most flexible solution available. A key feature of the nRF5x Series and their associated software architecture and S-Series SoftDevices is the possibility for Over-The-Air Device Firmware Upgrade (OTA-DFU) over Bluetooth LE. The DFU application allows to update nRF5 devices using Secure or Legacy DFU bootloader from nRF5 SDK version 4.3 or newer. The firmware should be in .zip file format, prepared using "nrf util" (https://github.com/NordicSemiconductor/pc-nrfutil).
Every shipping app on the App Store has gone through the same decisions you're working through right now: which screenshot goes first, what caption sits over it, which device frame to show, what color the background should be. The 6 screenshots above are nRF Device Firmware Update's answers to those questions — they're public, they're real, and they made it through Apple's review.
What the numbers say: nRF Device Firmware Update runs a dark set with one background colour (#040404) carried across every screenshot — the listing reads as a single poster when the shots sit side by side in search results. The accent colour we picked up, #04ACCC, is the one to reuse for badges, arrows and highlighted words if you borrow this look. Hit Use this style to open the editor with these exact colours and drop your own screenshot in.
Notice the first screenshot in particular. It's the one users see in search results and on the product page, and it's where most apps spend their best caption and tightest design. Look at the proportion of background to phone, where the text sits, what one thing the image is trying to communicate.
Want to see how other Developer Tools apps approach the same problem? Browse more Developer Tools apps in the showcase.
Open LaunchShots and design your App Store & Google Play screenshots — pick a device frame, drop captions, ship in minutes. Free, in your browser.
Open the screenshot editor →Closest background + accent colours among the listings we've analysed — useful when you want to see the same palette handled by a different team.