Derive Dark Theme Tokens while Checking Text Contrast Relationships

How to Use This Tool

Transform light tokens into editable dark candidates and report WCAG contrast for text pairs. Generate dark-mode candidates from light-theme hex tokens, preserve token names, calculate text/background contrast, and export CSS variables locally.

The work this page finishes

Simply inverting a light palette can destroy semantic emphasis and leave text pairs unreadable, while hand conversion loses the original token mapping. For Dark Mode Palette, keeping source order beside the computed artifact lets a user repair only the failed entries and reproduce the same batch later.

Deterministic workflow

Apply a role-specific deterministic RGB transform, retain safe token names and calculate WCAG relative-luminance contrast between generated text tokens and the first generated background. For Dark Mode Palette, a run is capped at 5,000 items and 2 MB, preventing an accidental oversized paste while preserving successful rows when another row fails.

Why a dedicated interface helps

Use the candidates as a starting point, then inspect every real component, state, elevation and non-text contrast relationship before shipping. For Dark Mode Palette, a purpose-built form exposes every assumption and returns the same ordered structure on every run, which is more practical than reconciling shifting conversational output.

Assumptions

• Role labels are background, text or accent.
• The first background token is the contrast reference.
• Hex colors are opaque sRGB values.

For Dark Mode Palette, keep an untouched copy for comparison after import; the browser performs the work locally, but local software and extensions are not controlled by this page.

Limitations and review boundary

This is not an accessibility certification: the transform is not perceptually uniform, cannot infer token pairings, brand intent or color vision performance, and checks only generated text against one background. For Dark Mode Palette, the implementation neither follows user-entered links nor evaluates their contents, and it displays material as plain text rather than active HTML.

Verification and provenance

Fixtures derived from the displayed rule and W3C WCAG 2.2 — Contrast (Minimum) were reviewed on 2026-08-26; they include normal, empty or invalid, and partial-failure behavior. The sample preserves five semantic token names, emits dark CSS variables and reports the lowest generated text contrast against the first background.