Sampled from 6 of STEP File Viewer's App Store screenshots — background, accent and theme, measured by LaunchShots (not something Apple publishes).
#ECECEC bg
#CFCFCF
#7CD4F4 accent
#111111 text
STEP File Viewer is a lightweight yet powerful tool for viewing .step and .stp files on macOS, iPad, and iPhone. Key Features • View STEP models in 3D with rotate, pan, and zoom controls using perspective projection. • Display 3D models in solid, shaded, or wireframe modes. • Load and view IGES/IGS models. • Supports assembly-level colors and exploded views (requires the model to include assembly data). • Parse and load STEP models as assemblies • Support PMI annotations, dimension details, and model information panels in AP242 models for easier design review. • Measure auto-detected hole features, bounding box dimensions, point-to-point distances, diameter/radius, and angles to verify key dimensions more quickly. • Pin review notes on the model to record issues, jump back to each note’s viewpoint, and export a review report as PDF with screenshots. • Apply axis-aligned sectio…
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 20 screenshots above are STEP File Viewer's answers to those questions — they're public, they're real, and they made it through Apple's review.
What the numbers say: STEP File Viewer runs a light set where the background shifts from screenshot to screenshot (first shot #ECECEC) — each image has to stand on its own, so the captions carry more of the story. The accent colour we picked up, #7CD4F4, 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.