How Does ColorSlurp Check Color Contrast and Accessibility?

Updated

ColorSlurp checks contrast by comparing two colors you supply and reporting whether they meet standards such as WCAG and APCA. If a pair fails, it offers a one-click fix that adjusts the background, the foreground, or both evenly. This is useful when you already have a color pair in a design and need to know whether it is accessible before shipping.

What the contrast checker does

The feature is described on colorslurp.com as a Color Contrast Checker that lets you "instantly check the contrast of two colors in your designs to meet web standards such as WCAG, APCA, and more."

Two things follow from that description:

  • Input is a pair of colors. You are checking one color against another, not scanning an entire design automatically.
  • Output is a standards verdict. The tool tells you whether the pair passes the referenced accessibility standards.

The site does not publish the exact pass/fail thresholds, the specific WCAG conformance level, or the APCA version used. Treat the checker as a fast first pass, and confirm final numbers against the official WCAG or APCA documentation for your target level.

How to check a pair

  1. Get both colors into ColorSlurp. You can pick them from anywhere on screen with the precision magnifier, or paste a color from the clipboard to edit it.
  2. Open the contrast checker and assign the two colors as the pair you want to test — in practice this means the text color and its background.
  3. Read the result. ColorSlurp reports whether the combination meets the referenced standards.
  4. If it fails, use the one-click fix and choose whether to adjust the background, the foreground, or both evenly.

The expected result is a corrected pair that passes, with the adjustment applied to whichever side you chose. Adjusting "both evenly" splits the change rather than pushing all of it onto one color, which helps when neither the text nor the background color is free to move.

Why the fix options matter

A failing contrast ratio can be resolved in more than one way, and the right choice depends on your constraints:

Situation Sensible fix
Brand color is fixed for text Adjust the background
Background is fixed (e.g., a photo or brand surface) Adjust the foreground
Both colors are flexible Adjust both evenly to preserve the relationship between them

Because ColorSlurp supports modern color spaces including OKLCH, LAB, Display P3, RGB, HSL, and CMYK, you can make these adjustments in the space that suits the design rather than being locked to one model.

Fitting it into a color workflow

The contrast checker is one part of a broader toolset on the same site. Colors you pick can be named, saved into palettes, grouped into projects, and synced across Mac and iOS devices in real time. Palettes export to formats including Sketch, Procreate, .ase, images, PDF, CSS, Sass, Swift, HTML, JSON, and .clr.

That matters for accessibility work in a specific way: once you have fixed a pair, you can save the corrected colors as a named palette and export them straight into CSS, Sass, Swift, or HTML, so the accessible values reach the codebase instead of living only in the picker.

Limits to keep in mind

  • The checker compares two colors at a time. It is not a full-page or full-app audit.
  • The site does not state which WCAG level or APCA version the results map to, so verify against the standard you are required to meet.
  • ColorSlurp is available for Mac and iOS; the site does not describe a Windows, Android, or web version.

For a quick pass on a text/background pair, the checker plus the one-click fix covers the common case. For a formal accessibility sign-off, use it to get close and then confirm the final ratios against the official standard.