Accessibility Lab

Accessibility Lab turns the active theme's readability and status colors into an inspectable report. It works with Syntalume themes and with other installed themes that VS Code makes available to the extension.

Run:

Syntalume: Open Accessibility Lab

What the report checks#

  • Audited foreground/background pairs and their WCAG contrast ratios.
  • Git added, modified, and deleted states.
  • Test pass/fail and diagnostic error/warning states.
  • Diff insert/remove and bracket-level separation.
  • Terminal ANSI green/red and yellow/blue separation; missing ANSI keys are reported as missing rather than silently replaced.
  • Approximate protanopia, deuteranopia, and tritanopia simulations for those status pairs.

Every CVD view shows the actual transformed color swatches alongside the distance heuristic, so you can review the appearance rather than relying on a number alone.

The color-vision-deficiency distance is a review heuristic, not a medical test or a WCAG conformance claim. A flagged pair means it deserves visual review; it does not by itself mean that a theme is inaccessible.

Optional status axes#

The Lab includes two previewable status-axis presets:

  • Sky / orange: sky blue for positive states, burnt orange for negative states, magenta for warnings, and green for information.
  • Teal / violet: teal for positive states, violet-magenta for negative states, amber for warnings, and blue for information.

Both are reviewed by the same approximate protanopia, deuteranopia, and tritanopia heuristic shown in the Lab. They are visual-review aids—not medical advice or WCAG conformance claims. Selecting an axis changes only the preview. Apply selected axis shows a modal confirmation before anything is written. Every role swatch reaches at least 4:1 against both black and white in the release tests, so the axes remain viable across light and dark editor themes.

An applied axis uses only the public User-level workbench.colorCustomizations setting, inside the active theme's [Theme Name] block. Its exact owned keys are:

gitDecoration.addedResourceForeground
gitDecoration.untrackedResourceForeground
gitDecoration.modifiedResourceForeground
gitDecoration.deletedResourceForeground
testing.iconPassed
testing.iconFailed
testing.iconQueued
testing.iconSkipped
editorError.foreground
problemsErrorIcon.foreground
editorWarning.foreground
problemsWarningIcon.foreground
editorInfo.foreground
problemsInfoIcon.foreground
diffEditor.insertedTextBackground
diffEditor.removedTextBackground
terminal.ansiGreen
terminal.ansiBrightGreen
terminal.ansiRed
terminal.ansiBrightRed
terminal.ansiYellow
terminal.ansiBrightYellow
terminal.ansiBlue
terminal.ansiBrightBlue

Choose Exact reset or run Syntalume: Reset Accessibility Status Axis to restore each owned key to its value—or absence—before Apply. Unrelated keys you add to the same theme block later remain. If you manually change one of the 24 owned keys after Apply, that newer value wins while reset still restores the other unchanged Syntalume-written keys.

Share or repair#

Choose Copy health report to put the complete JSON report on the clipboard, or Save JSON to write it where you choose. The report names theme color keys and measurements; it does not include source code, file paths, project names, or environment context names. It also identifies the selected status axis and includes the exact color-key map that applying that axis would write.

Use Display stress preview to switch between the original colors, a bright-room projector-washout approximation, and a low-quality-display approximation with reduced chroma and quantized channels. These are honest, device-agnostic review heuristics—not calibrated hardware profiles. They are read-only and reversible because switching them changes only the Lab preview; it writes no editor setting. Copy and Save export the selected stress report.

Choose Repair contrast to run Syntalume's reversible, theme-scoped contrast repair. The repair adjusts lightness while preserving hue and leaves every other theme untouched. Run Syntalume: Repair Theme Contrast again to remove the repair exactly per color and syntax rule: later manual edits win, every other unchanged repair entry restores, and unrelated entries remain. General Reset removes repairs for every theme through the same exact, cross-feature history.

The shipped high-contrast themes and Frost Colorblind remain useful starting points. Accessibility Lab is for verifying the exact active combination after Tune, extension surfaces, and personal overrides are included.