Meet Color Truth — See your design the way users actually see it

Developer Tools

Color Truth

See your design the way users actually see it.

Every feature, from the first launch.

No account, no login, no cloud. Everything runs on your device and works fully offline — nothing in this post is hidden behind a wall.

What Color Truth does

1 in 12 men and 1 in 200 women have color vision deficiency. Most designers find out their button is invisible to red-green colorblind users only after launch.

Color Truth is a 3-in-1 accessibility tool that fits in your pocket:

Color-blind image simulator Load any photo or screenshot. Toggle through eight vision modes (normal, protanopia, protanomaly, deuteranopia, deuteranomaly, tritanopia, tritanomaly, achromatopsia) and see what each user sees. Side-by-side compare. Save the simulated image to share with a teammate.

WCAG contrast checker Pick two colors. Get the contrast ratio and the WCAG level (AA, AAA, fail) for regular and large text. Suggested adjustments to reach AA.

Palette extractor Point camera or load a photo. App extracts 8 dominant colors via k-means clustering on-device. Tap any color to get hex, RGB, HSB, and contrast pairs that work.

Free. No subscription. All math runs on-device. The simulator uses validated color transformation matrices from published color-vision research.

A look inside

Tap any screenshot to open the full-resolution version.

What's inside

Vision simulator — Load image, toggle 8 color-vision modes
Contrast checker — Two-color picker → contrast ratio + WCAG level
Palette extractor — Image → 8 dominant colors via k-means
Side-by-side compare — Original vs simulated split-view
Save & share — Export simulated image to share sheet

Why we built it

Color-blind simulation tools exist on desktop (Sim Daltonism, Color Oracle) but iOS versions are sparse and most charge subscription. WCAG checkers are web-only or browser extensions. Designers reviewing screenshots on their phone have no native iOS toolkit.

What makes it different

Color Truth is the only iOS app combining the three workflows designers actually use — image color-vision simulation, WCAG contrast pair-checking, and on-device palette extraction — using validated transformation matrices and Core Image filters. Free, no subscription. Works on plane / WiFi-less coffee shop.

Who it's for

Built for anyone who values fast, private, on-device software with a calm, focused UX.

In one line: See your design the way users actually see it.

Try it

See the Color Truth app page for the full feature list, the info table, and support links.

Use Color Truth, found a bug, or have a feature request? Comments are open below — anonymous is fine.