This module produces WCAG contrast ratio measurement and scoring. It's an accessibility standard, intended to make sure websites have high enough contrast to be readable by everyone, including people with low vision and age-related vision problems. This module is a low-level utility, useful for its implementation of the underlying math: to test a page, you'll want to use something like Google Chrome’s Lighthouse tools, or the axe extension for Chrome and Firefox.
I (personally, speaking as Tom) have doubts about the universality, accuracy, and application of this particular standard. High contrast is a good value, but I argue that the standard is over-strict and doesn't precisely match human perception.
Get the contrast ratio between two relative luminance values
Parameters
Examples
luminance(1, 1); // = 1Returns number contrast ratio
Get a score for the contrast between two colors as rgb triplets
Parameters
Examples
rgb([0, 0, 0], [255, 255, 255]); // = 21Returns number contrast ratio
Get a score for the contrast between two colors as hex strings
Parameters
Examples
hex('#000', '#fff'); // = 21Returns number contrast ratio
Get a textual score from a numeric contrast value
Parameters
contrastnumber
Examples
score(10); // = 'AAA'Returns string score