Color is one of the most powerful tools in a designer's toolkit. It communicates brand identity, establishes hierarchy, and evokes emotional responses. But if your color choices exclude people with visual impairments, you are undermining both your reach and your values. At Kosmoweb, we believe that accessible color palettes are not a constraint on creativity; they are a framework that makes design work for everyone.
Why Accessibility Matters
Approximately one in twelve men and one in two hundred women have some form of color vision deficiency. Add in situational impairments, like reading a screen in bright sunlight or with reduced screen brightness, and the number of people affected by poor color choices grows substantially. Inaccessible color palettes do not just fail compliance standards; they fail real people trying to use your product.
Accessibility is also a legal consideration in many jurisdictions. The European Accessibility Act, which takes effect in 2025, will require digital products and services to meet specific accessibility standards. Businesses that ignore these requirements risk both legal liability and reputational harm. Designing with accessibility in mind from the start is far less expensive than retrofitting a finished product.
Start With Contrast
Contrast ratio is the foundation of color accessibility. The Web Content Accessibility Guidelines specify minimum contrast ratios of 4.5:1 for normal text and 3:1 for large text at the AA level. AAA compliance requires 7:1 and 4.5:1 respectively. These ratios ensure that text remains legible across a wide range of visual abilities and viewing conditions.
We check contrast ratios obsessively during the design phase. Tools like the WebAIM Contrast Checker and the built-in accessibility inspectors in Chrome and Firefox DevTools make this straightforward. When we designed the interface for a Prague-based coworking space booking platform, we discovered that our initial brand green failed contrast requirements against white backgrounds. Rather than abandoning the brand color, we darkened it by two shades, maintained the brand feel, and achieved AA compliance across all text elements.
Pick a Base Color
Start your palette with a single base color that represents your brand. From there, derive a range of tints and shades that can serve different functional roles: primary actions, secondary elements, backgrounds, borders, and text. Each derived color should be tested for contrast against every background it will appear on.
We find it helpful to build palettes with at least five steps from light to dark for each hue. This provides enough variation to create visual hierarchy without introducing colors that clash or fail accessibility checks. A palette is not just a collection of attractive colors; it is a system where every combination has been validated for legibility and clarity.
For a nonprofit client focused on environmental education, we built a palette rooted in forest green. The lightest tint served as a subtle background. The mid-range shade was used for icons and decorative elements. The darkest shade became the primary text color on light backgrounds. Every pairing was tested and documented before any design work began.
Test Different Combinations
Contrast ratios give you a pass-fail metric, but real-world readability depends on more than numbers. Test your color combinations in context, on actual page layouts with real content. A color pair that passes contrast checks might still feel visually harsh or create an unpleasant vibration effect when used for body text. Conversely, a pair that barely meets the threshold might work well for large headings but fail for small print.
Test at different screen brightnesses and on different display types. An OLED screen renders colors differently from an older LCD panel. A laptop in a sunlit cafe presents different challenges than a desktop monitor in a dim office. We build test pages with representative content and circulate them across team members using different devices to catch issues that automated tools miss.
Use Colorblind-Friendly Palettes
Color should never be the sole means of conveying information. If a form field turns red to indicate an error, pair that color change with an icon and a text message. If a chart uses color to distinguish data series, add pattern fills or direct labels. This principle, drawn from WCAG guideline 1.4.1, ensures that meaning is preserved even when colors are indistinguishable.
Simulate color vision deficiencies during the design process. Tools like Stark, Sim Daltonism, and the vision simulation filters in Chrome DevTools let you see your design as someone with protanopia, deuteranopia, or tritanopia would. We run these simulations on every project and have caught issues that would have been invisible without them. On a data dashboard for a logistics company, our original red-green status indicators were indistinguishable under deuteranopia simulation. We switched to a blue-orange scheme with icon overlays, and the dashboard became usable for the entire team, including two employees with color vision deficiencies.
Keep It Real
Accessible design is not a checkbox exercise. It is a commitment to building products that respect the full diversity of human perception. At Kosmoweb, we integrate accessibility reviews into every stage of our design process, from initial palette exploration through final QA. The time investment is modest compared to the breadth of impact.
Start with contrast, build systematically, test rigorously, and never rely on color alone to convey meaning. These principles will not limit your creativity. They will sharpen it by giving you constraints that push toward better, more thoughtful design decisions. An accessible color palette is simply a good color palette, one that works for as many people as possible under as many conditions as possible.