Color and sensory
Sensory characteristics
Perceivable
Level A
Benefits: Blind and low-vision disabilities.
Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, size, visual location, orientation, or sound.
How to pass
- Can the user access instructions for using the content, even when they cannot perceive shape or size or use information about spatial location or orientation?
- Are descriptions of controls solely via references to visual or auditory cues avoided?
- Is additional information provided other than shape and/or location?
- Does positioning, color, and labeling help identify the information?
Use of color
Perceivable
Level A
Benefits: Colorblind disabilities.
Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.
How to pass
- Verify that color alone is not used to convey important information.
- Can all of the information be understood when viewing the page in grayscale?
- Can all of the page functions be performed when viewing the page in grayscale?
Contrast
Perceivable
Level AA
Benefits: Low-vision and colorblind disabilities.
The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following:
- Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1.
- Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration,that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.
- Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.
How to pass
- Is the color contrast of the text and its background readable by low-vision users?
- Using a color contrast tool - are color contrast ratios at least 4.5:1 for text that is < 18 point/24 px, and for bold text that is < 14 point/18.5 px?
- Using a color contrast tool - are color contrast ratios at least 3:1 for large-scale text that is at least 18 point/24 px, and for large-scale bold text that is at least 14 point/18.5 px?
- Is there a text that is only decorative and conveys no information? (Decorative text does not need to meet color contrast guidelines)