Use appropriately sized buttons and links, and provide whitespace around them, to allow people with reduced dexterity to use the carousel more easily. This also benefits people using touch screens, such as on mobile devices. Buttons and links that are not inline in a block of text should be at least 44 × 44 CSS pixels.
Ensure sufficient contrast between the foreground and the background of text, links, and buttons. This can be a challenge when text or buttons are positioned on top of images. In that case, a (semi-) opaque background color can help to maintain the contrast regardless of the image used.
Indicate Button Status
Since the navigation buttons added to the carousel are typically small, it is important to indicate their status both in color and shape (in addition to proper naming and labeling). This makes it easier for people to differentiate the buttons and their current status.
In the following example, a filled square is used for buttons associated with items currently not shown. The button for the item shown has rounded corners and inverted colors. When users hover over these buttons using a mouse or focus them using a keyboard, their border is dotted.
Related WCAG resources
These tutorials provide best-practice guidance on implementing accessibility in different situations. This page combined the following WCAG success criteria and techniques from different conformance levels:
1.4.1 Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Level A)
1.4.3 Contrast (Minimum): 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.
2.4.7 Focus Visible: Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible. (Level AA)
2.5.5 Target Size: The size of the target for pointer inputs is at least 44 by 44 CSS pixels except when:
Equivalent: The target is available through an equivalent link or control on the same page that is at least 44 by 44 CSS pixels;
Inline: The target is in a sentence or block of text;
User Agent Control: The size of the target is determined by the user agent and is not modified by the author;
Essential: A particular presentation of the target is essential to the information being conveyed.