Start with the experience, not the color palette
Contrast is the difference in brightness between elements such as text and its background. A color pairing may look clear on a designer’s monitor yet be difficult to read for someone with low vision, especially at small sizes or in bright surroundings. Checking contrast helps visitors find information, complete forms and recognize what they can click.
Begin with a short inventory of the places people need to read or act: body copy, headings, links, form labels, error messages and buttons. Include the pages that carry important tasks, such as contacting the organization or registering for an event. This gives a small team a manageable starting point instead of turning the review into an open-ended search for every color on the site.
Check text against its actual background
For standard text, the Web Content Accessibility Guidelines (WCAG) 2.x AA contrast threshold is 4.5:1. For large text, it is 3:1. Large text means at least 18-point regular or 14-point bold; on typical web layouts, that is roughly 24 and 19 CSS pixels. A contrast checker can calculate the ratio when you enter the foreground and background colors. Use the smaller-text threshold if you are unsure which size applies.
Check the colors as visitors actually see them, not just the values in a brand guide. Light gray text on white may fail even if the same gray works on a darker panel. Text over a photograph needs particular care because the background changes across the image and may shift when the page resizes. A solid backing or sufficiently dark overlay is often more dependable than trying to find one text color that works everywhere on a photo.
Imagine a community group with a pale green announcement panel and white text. If the checker shows insufficient contrast, the group could use darker text, deepen the panel color or place the message on a solid surface. Retest the revised pairing rather than relying on how it looks at first glance.
Review buttons as both words and controls
A button has two contrast questions. First, can people read its label against the button fill? Apply the text thresholds to the label. Second, can people identify the button’s shape against the surrounding page? Where its boundary is needed to recognize it as a control, WCAG 2.x AA calls for at least 3:1 contrast between that visual boundary and adjacent colors. A border can help a pale button remain visible on a pale page.
Check every meaningful button state: default, hover, keyboard focus and any selected state. A dark button might pass in its default state but become too pale when hovered over. A focus outline can also disappear against the page background. Do not use color change alone to communicate an important state; a visible outline, underline or text cue can make the change easier to notice.
For example, a “Send message” button with white lettering on a medium-blue fill needs a text-contrast check. If the fill sits clearly against a white page, its shape may be easy to find. If a secondary button uses a white fill on that same page, give it a sufficiently distinct border and check that the border remains visible.
Use a repeatable checking workflow
Choose one representative page and list each text-and-background pairing and each button style. Use a contrast checker to record the ratio for each pairing, along with whether it is used for normal text, large text or a control boundary. Check rendered colors when transparency, gradients or images are involved: the color written in a stylesheet may not be the color visitors see.
Next, work through the page with a keyboard to reveal focus states, then inspect it at a narrow screen width and with text enlarged. These checks do not replace measured contrast, but they can expose labels crossing into a different part of an image, buttons wrapping awkwardly or focus indicators that are hard to spot. Fix shared styles first, such as the site’s body-text color or primary button, then revisit individual exceptions.
Keep a brief record of what changed and retest the affected pages. When adding a new page or campaign graphic, reuse checked color combinations where possible. That small habit makes contrast part of everyday publishing rather than a problem saved for a future redesign.
Aim for clarity beyond the minimum ratio
A passing ratio is a useful baseline, not a guarantee that everyone will find a page comfortable to use. Tiny text, crowded spacing and labels that vanish during an interaction can still create barriers. Clear wording, readable type sizes and controls that look actionable support the work you have done on color.
Prioritize the paths visitors rely on most, then extend the review across the site. If your organization cannot fix everything at once, correcting body text, navigation, forms and primary actions can make an immediate practical difference while you plan the remaining updates.
