Color blindness
Color blindness is a class of visual conditions in which the perception of certain colors is impaired or absent. The most common form, red-green color blindness, affects roughly 8% of men and 0.5% of women of Northern European descent.
Detailed explanation
The most common types are protanopia (red weakness), deuteranopia (green weakness), and tritanopia (blue weakness). Less common is achromatopsia (total color blindness, perceiving only greyscale). Color blindness is genetic in most cases and present from birth.
WCAG 2.1 SC 1.4.1 (Use of Color) at Level A requires that color is not the only means of conveying information — error states, required-field indicators, and chart series must have a non-color cue (icon, text label, pattern). SC 1.4.3 (Contrast Minimum) at AA requires sufficient luminance contrast which also helps low-vision users regardless of color perception.
How this applies to Shopify stores
Color-only inventory indicators and swatches without a programmatic or visible non-color cue are common review points. AccessComply can surface selected DOM and style patterns, but understanding whether color is the only conveyed distinction often requires manual evaluation.
What merchants should check next
Treat this term as a practical audit prompt, not just a definition. Check the storefront pages where the concept shows up in real customer journeys: product discovery, add-to-cart, cart drawer, checkout handoff, account login, and support contact flows. If the issue affects code, verify the rendered HTML and computed browser output after the theme change. If it affects copy or media, keep the merchant-facing wording accurate and easy to maintain.
Primary source: w3.org