Understanding Image and Color Contrast – A Complete Guide

Image and color contrast are fundamental in UX design. The right ratio makes your content much more legible to users. It also makes it easily available to people with visual impairments, color blindness, light sensitivity, and age-related vision changes. You can use resources, such as this contrast checker tool from achecher.ca, to determine whether your content aligns with the latest WCAG standards.

Defining Image and Color Contrast

Image and color contrast determine the visibility and readability of any digitally available content. They measure the difference in luminance and hue between foreground elements (such as text or icons) and their background. The higher the contrast is, the more accessible the content is.

The Web Content Accessibility Guidelines (WCAG) 2.2 define success criteria across levels A, AA, and AAA. Level AA, the most common target, requires a 4.5:1 ratio for small text (under 18pt) and a 3:1 ratio for large text (18pt+ or bold). Graphics, icons, and images follow suit – essential elements must meet these ratios against their backgrounds.

You can use various tools to measure the contrast ratio of your content, flag issues, and generate and preview compliant palettes. Browser extensions like Stark or Axe DevTools scan pages live. Of course, you should also test with real users to make sure your content meets accessibility standards.

The same applies to images – there’s a wide range of tools and resources (e.g., WAVE and Lighthouse) you can use to scan your content and flag issues. The Windows Magnifier feature can help you with manual checks in high-contrast modes. You can simulate color blindness with Coblis or Chrome’s “Force Dark” mode. Again, real user testing is an integral part of the process.

When it comes to colors, you can use dark text (#000000) on light backgrounds (#FFFFFF) for a perfect 21:1 ratio, passing all WCAG levels (A, AA, AAA). Tools like Coolors generate compliant palettes. Avoid reds/greens for color-blind users (8% of men, 0.5% of women). You can use blue/orange instead.

Whether you’re choosing photographs of casino floors and card tables or anything else, busy photos and images are also not recommended for an accessible UX design. They create inconsistent luminance across pixels, drop contrast ratios below the WCAG requirements, and lead to cognitive and visual strain.

Instead, you can use simple, low-detail images. You can also add semi-transparent overlays (e.g., RGBA (0,0,0,0.6)) to unify backgrounds and make sure text pops reliably. There are different guides you can look at. If you’re a photographer, for example, these tips on capturing desert landscapes could be very helpful.

The Many Reasons Image and Color Contrast Matter

According to the World Health Organization, more than 2.2 billion people worldwide live with some vision impairment. Yet, image and color contrast are still the most common issues flagged in digital content. This means that some of this content remains at least partially unavailable to many people.

The 2025 WebAIM report on the accessibility of the top 1 million homepages paints a concerning picture. 94.8% of the evaluated homepages showed WCAG compliance failures. Massive 79.1% of them contain low contrast text. And while there’s been some improvement compared to data from previous WebAIM reports, there’s still a long way to go.

To improve accessibility and boost inclusivity, countries all around the world have introduced strict compliance rules. Non-compliance risks fines and lawsuits. In the US, particularly, the Americans with Disabilities Act (ADA) mandates accessible digital experiences, with lawsuits against non-compliant sites rising 20% annually.

The ultimate goal is to guarantee that people with disabilities have access to the same opportunities as everybody else. However, users without any visual impairment also benefit from image and color contrast. We’ve all been in a situation where the sun is shining brightly, and we’re desperately trying to read low-contrast text on our phones.

People working late and scanning documents on dimmed screens can experience eye strain from subtle gradients in images. Not to mention that search engines like Google put major focus on accessibility, and failures in this area could negatively impact your content’s performance.

The Future Ahead

Regular audits of your content are crucial for long-term success. You can integrate contrast checks into design workflows using Figma plugins or Adobe Color. For developers, CSS variables (e.g., –text-primary: #1A1A1A;) enable theme switching. Frameworks like Tailwind CSS include utilities like text-black/90 for AA compliance.

Whenever possible, go for AAA (7:1 for normal text), especially for critical interfaces. There are many AI tools to help you flag and resolve issues. That said, don’t forget the human element, with real user testing. Proper image and color contrast will greatly improve visual hierarchy and consistency and make your content more accessible and inclusive.