Relying solely on color to refer to content or functionality makes an ebook inaccessible. For example, distinguishing internal or external links by color alone (such as blue) prevents users of assistive technologies or those with color vision deficiencies from identifying them.

Objectives

• Ensure information is accessible to users whose reading tools, assistive technologies, or visual impairments (such as color blindness) prevent them from perceiving or differentiating colors.
• Improve content accessibility for people with disabilities.

Implementation

• Provide an alternative means of conveying information in addition to color. For example, use semantic markup (such as text styling) or include patterns, textures, or borders in maps and charts.

Control

• Visually compare the ebook’s standard display against a version where colors are disabled (e.g., grayscale) to ensure information remains clear.