๐ช๐ต๐ฎ๐ ๐๐ฐ๐ถ๐ฒ๐ป๐ฐ๐ฒ ๐๐ฎ๐๐ ๐ฎ๐ฏ๐ผ๐๐ ๐ฏ๐น๐ฎ๐ฐ๐ธ & ๐๐ต๐ถ๐๐ฒ ๐ฐ๐ผ๐บ๐ฏ๐ถ๐ป๐ฎ๐๐ถ๐ผ๐ป๐ ๐ถ๐ป ๐จ๐ ๐ฑ๐ฒ๐๐ถ๐ด๐ป
One thing that surprised me when I started reading more about readability research: pure black and pure white are often NOT the most comfortable combinations for users. Which is interesting, because in digital design we are taught almost the opposite: โmaximum contrast = maximum accessibilityโ.
But readability research is much more nuanced than that.
Several studies found that people generally read dark text on light backgrounds faster than white text on black backgrounds (โpositive polarity advantageโ).
And one unexpected reason is something called halation: with very bright text on very dark backgrounds, letters can appear to โglowโ, blur slightly, or bleed into the background. This effect becomes even stronger:
with smaller font sizes
on low-quality screens
during long reading sessions
for users with astigmatism
in low-light environments
Some users describe it as โtext vibrating slightlyโ, which explains why interfaces that look visually โcleanโ in design files can become tiring surprisingly fast in real life.
Another interesting point: researchers studying eye movement and readability found that colour combinations directly influence reading speed, visual fatigue and focus stability.
And accessibility makes this even more complicated because there is no universally โperfectโ combination. For some people:
dark interfaces reduce light sensitivity
help with migraines
feel calmer in low-light environments
While for others:
dark mode creates blurrier text edges
increases eye strain
reduces reading speed
makes concentration harder over time
Which is why accessibility is not only about passing WCAG contrast ratios. A technically compliant interface can still create visual fatigue, cognitive overload, headaches, slower reading, missed information and attention loss.
Another thing I find fascinating: research on readability suggests that our eyes do not only react to colour itself, but to luminance relationships between elements.
This is why many accessible design systems avoid:
โ pure #000000 on #FFFFFF
โ pure #FFFFFF on #000000
And instead use softer combinations like:
โ #1A1A1A on #FAFAFA
โ #222222 on #F5F5F5
โ #EAEAEA on #121212
โ #F1F1F1 on #1E1E1E
A few practical things worth checking:
Read your interface for 15โ20 minutes continuously
Test it late at night and outdoors in sunlight
Reduce screen brightness and check readability again
Zoom text to 200%
Test with users who have astigmatism or visual fatigue
Check hover/focus states separately from static screens
Donโt evaluate colours only inside Figma
The more I work on accessibility, the more I realise that readability is deeply physical, not just visual.
