Final answer:
To ensure accessible design, color contrasts in web content should have a color contrast ratio of at least 4.5:1 for standard text, which is about 88%. For graphical elements, a minimum contrast ratio of 3:1 is recommended, as per WCAG guidelines.
Step-by-step explanation:
When it comes to accessible design, color value contrasts are crucial to ensure content is easily discernible by people with visual impairments. While there's no precise percentage mentioned in the question, best practices in web content accessibility suggest that text and images of text should have a color contrast ratio of at least 4.5:1 which is approximately 88% for standard text and 3:1 for large text.
For graphical elements and user interface components, a minimum contrast ratio of 3:1 is recommended. This ensures that viewers with different types of color deficiencies can still distinguish content effectively. It also supports those working in environments with screen glare or where a screen may not be optimally positioned. Achieving sufficient color contrast is a key requirement of the Web Content Accessibility Guidelines (WCAG), which provide a range of recommendations for making web content more accessible.