Sampled from 3 of REPL's App Store screenshots — background, accent and theme, measured by LaunchShots (not something Apple publishes).
#040404 bg
#272727
#ECD444 accent
#FFFFFF text
Reading the caption text from the screenshots in your browser…
REPL is a native code runner for Python and JavaScript — built for the AI era. When your favorite AI gives you code, where do you test it? REPL lets you paste code directly from AI conversations, run it instantly, and copy the results back. No laptop required. FEATURES - Native Python 3.11 — Real CPython running locally on your device, not a web interpreter - JavaScript Engine — Powered by iOS JavaScriptCore - Persistent State — Variables survive between runs, like a true REPL - Share Sheet — Send code from any app directly to REPL - History — Access your last 50 code runs - Smart Parsing — Automatically extracts code from markdown fences - Offline — Everything runs locally, no internet needed - Dark Mode — Easy on the eyes BUILT FOR AI WORKFLOWS Copy code from ChatGPT, Claude, Gemini, or any AI assistant. Paste into REPL. Tap Run. See results. Copy output back to your conversation…
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 4 screenshots above are REPL's answers to those questions — they're public, they're real, and they made it through Apple's review.
What the numbers say: REPL 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, #ECD444, 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.