Articles by
Facundo Corradini

I'm a front-end developer for Argentina, an UX enthusiast, a performance hooligan, and the very best cebador de mates ever. Probably.

Switch font color for different backgrounds with CSS

Ever get one of those, "I can do that with CSS!" moments while watching someone flex their JavaScript muscles? That’s exactly the feeling I got while watching Dag-Inge Aas & Ida Aalen talk at CSSconf EU 2018.

They are based in Norway, where WCAG accessibility is not a just good practice, but actually required by law (go, Norway!). As they were developing a feature that allows user-selectable color theming for their main product, they faced a challenge: automatically adjusting the font color based on the selected background color of the container. If the background is dark, then it would be ideal to have a white text to keep it WCAG contrast compliant. But what happens if a light background color is selected instead? The text is both illegible and fails accessibility.

They used an elegant approach and solved the issue using the "color" npm package, adding conditional borders and automatic secondary color generation while they were at it.

But that’s a JavaScript solution. Here’s my pure CSS alternative.