react-transition-group/www/src/css/_variables.scss

$syntax-hue: 230;
$syntax-saturation: 1%;
$syntax-brightness: 98%;

// Monochrome -----------------------------------
$mono-1: hsl($syntax-hue, 8%, 24%);
$mono-2: hsl($syntax-hue, 6%, 44%);
$mono-3: hsl($syntax-hue, 4%, 64%);

$hue-1: hsl(198, 99%, 37%); // <-cyan
$hue-2: hsl(221, 87%, 60%); // <-blue
$hue-3: hsl(301, 63%, 40%); // <-purple
$hue-4: hsl(119, 34%, 47%); // <-green

$hue-5: hsl(5, 74%, 59%); // <-red 1
$hue-5-2: hsl(344, 84%, 43%); // <-red 2

$hue-6: hsl(41, 99%, 30%); // <-orange 1
$hue-6-2: hsl(41, 99%, 38%); // <-orange 2

$syntax-fg: $mono-1;
$syntax-bg: hsl($syntax-hue, $syntax-saturation, $syntax-brightness);
$syntax-gutter: darken($syntax-bg, 36%);
$syntax-guide: fade($syntax-fg, 20%);
$syntax-accent: hsl($syntax-hue, 100%, 66%);