Color communicates a lot information on interfaces. But not so much for color blind users. They often have trouble distinguishing between different colored objects.
If you only use color as a visual cue on your buttons, it’ll make it hard to tell what the active state is. Instead of only using color, you should also use shapes on your buttons.
There are many buttons on a navigation bar, but it’s not easy to tell which is the selected one if you only use color. Many sites will add a contrasting color to the button label. This is hard for color blind users to notice.
Instead of only using color, add an underline to the button label. Colorblind users won’t have to guess which button is selected. They’ll notice it at a glance.
Another place where color blind users need more of a visual cue are segmented buttons. Many only use color fills to distinguish the different states. While this is clear to normal users, color blind users will have trouble telling them apart.
All they will see is a light color fill versus a dark color fill. It’s easy to wonder whether the light or dark color fill signals highlighting. Clear up the confusion by adding a checkmark icon next to the active state button label.
Toggle switches also face a visual cue problem for color blind users. When you only use color for on and off, it’s hard to tell the active state.
To make the states more clear, you can add an “on” and “off” label to the switches. Or, you can add a checkmark to the “on” state.
Color Is Not Enough
Color blindness affects a large percentage of the population. If you want to reach every user, communicating with color is not enough. Consider using checkmarks, underlines and labels as extra visual cues for clearer button states. Color blind users already have it harder than the rest of us. You can make their lives a little easier by doing a little more.