Use of Color
Color must not be the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.
What it requires
WCAG 2.0 SC 1.4.1 covers the 8% of users with color-vision differences (red-green color blindness is the most common) plus screen-reader users. Color-only signals — a red border on a form input that has an error, or a green checkmark for "in stock" — are invisible to those users without an accompanying non-color cue.
The fix: pair every color cue with text, an icon, a pattern, or a shape that conveys the same information. A form-input error gets a red border AND an error message AND an exclamation icon.
Common Shopify failure
Variant swatch picker where unavailable variants are greyed out with no text indication. Color-only "low stock" indicator (red dot only).
How to fix it
AccessComply rewrites variant swatches to include `aria-disabled` + a text "Out of stock" badge alongside the visual greying. For "low stock" indicators, the agent adds an accompanying `<span class="sr-only">Low stock</span>` text label.
Primary source: W3C — WCAG 2.0 Understanding 1.4.1