Classify colors as light or dark
Apply one explicit relative-luminance threshold for interface branching and labels.
#747474 - luminance 0.17465
dark
#757575 - luminance 0.17789
dark
#767676 - luminance 0.18116
light
See the exact boundary
PHPColor classifies colors with relative luminance greater than or equal to 0.179 as light. Values below it are dark.
Read the predicate and its input
Inspect luminance beside the boolean when the boundary matters to your application.
<?php
use PhpColor\Color\Color;
foreach (['#747474', '#757575', '#767676'] as $hex) {
$color = Color::parse($hex);
printf("%s %.15f %s\n",
$hex,
$color->getLuminance(),
$color->isLight() ? 'light' : 'dark',
);
}
// #747474 0.174647403655585 dark
// #757575 0.177888415983629 dark
// #767676 0.181164244249860 lightA class is not a contrast verdict
Light or dark describes one color under PHPColor's threshold. It does not evaluate a foreground and background pair.
LightRelative luminance is greater than or equal to 0.179.
DarkRelative luminance is below 0.179.
PairingUse a contrast calculation for two colors.
SemanticsThe predicate does not infer token roles or theme intent.