Level AWCAG 2.2
1.3.3 Sensory Characteristics
Instructions do not rely solely on sensory characteristics such as shape, size, visual location, orientation, or sound.
Why it matters
Color vision differences
About 8% of men and 0.5% of women have some form of color vision deficiency, so color-only cues can be unreadable.
Visual impairment
Instructions based only on position or shape — 'the button on the right', 'the round icon' — fail for users who cannot see.
Screen readers
They cannot perceive color or shape, so a text description is essential.
Cognitive impairment
Explicit text, rather than sensory cues alone, makes content easier for everyone to understand.
Live demo
Do not rely only on sensory characteristics
Instruction depends on color alone
“Press the red button to submit.”
How it may appear to a user with color-vision differences
“Press the ??? button to submit.”
Do not communicate information only through sensory cues such as color, shape, size, location, or sound. Text labels and icons make the meaning clear to everyone.
Understand through a persona
Ito (55) — Red-green color vision deficiency
When told 'please check the red error message', he cannot tell which one is red. Explicit text such as 'Error: incorrect password' makes it understandable.