WCAG 1.3.3: Sensory Characteristics
WCAG 1.3.3 Sensory Characteristics is a level A success criterion from WCAG 2.0. Instructions must not rely only on shape, colour, size or location, such as 'press the round green button on the right'.
People who cannot see colour or layout cannot follow those instructions.
How to test
Read help text aloud. If it only says where something looks, rewrite it.
How to fix
Name the control: 'Choose Add to basket' rather than 'use the green button'.
Example that fails
Help text says 'click the red link on the left'.
Example that passes the check
Help text says 'open Delivery times'.
Shopify
Edit theme help text and policy snippets so they name the link, not its colour.
WooCommerce
Update checkout notices that say 'the box on the right'. Name the field.
WordPress
Edit the paragraph so instructions name the control.
Wix
Change text boxes that point at colour or position so they name the button.