Short answer
Measure the actual text-background pair rather than relying on your monitor. WCAG establishes a 4.5:1 minimum reference for normal text, with specific rules and exceptions. Check final exports: transparency, photos and button states can change the measured pair.
Key verification: Every informational text has an identified background and state, reproducible measurement and final-asset review.
Sources and limitationsAn ad can retain a sharp phone number yet remain difficult to read when background and text are too similar. More saturation does not guarantee contrast. This guide reviews digital assets before publication, separately from brand-colour selection and complete site accessibility.
Define the measured text and background
Include phone, price, conditions and call to action. Record colour values and final size rather than just design-canvas dimensions. On photographs or gradients, check areas behind text and the actual crop. With transparency, measure the published composite colour rather than the isolated layer colour.
Numerical exercise using assumed luminances
| Fictional pair | Lighter luminance | Darker luminance | Calculated ratio |
|---|---|---|---|
| A | 1 | 0 | 21:1 |
| B | 0.45 | 0.10 | 3.33:1 |
Calculation uses (lighter luminance + 0.05) / (darker luminance + 0.05). For B, 0.50 / 0.15 is approximately 3.33:1. These are exercise inputs rather than a substitute for converting colour values under the applicable definition. Do not round a slightly failing measurement upwards to pass the threshold.
Text reference and check limitations
The WCAG minimum contrast explanation distinguishes normal text, large text and exceptions. Check applicability before selecting a threshold. Passing contrast does not establish readable size, navigation, accessible names or overall conformance. This worksheet reviews one component rather than certifying the website.
Corel and output review
Corel documents image colour modes. Retain an appropriate digital output and measure the final export with a contrast checker. Review normal and interaction states if used in a button. CallsIQ has not run a Corel test or claimed an unverified native contrast checker.
Sources and limitations
Documentary review: . Content type: Documentation-based guide with original exercise.
Sources describe terms and capabilities stated by their owners. Proposed protocols and fictional examples do not establish product tests performed by CallsIQ.
- WCAG minimum contrast explanationwww.w3.org
- image colour modesproduct.corel.com
Check current terms
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