nextcloud-server/apps/accessibility/css/highcontrastdark.scss

// SCSS variables
$color-main-text: #fff;
$color-main-background: #000;

$color-background-dark: lighten($color-main-background, 30%);
$color-background-darker: lighten($color-main-background, 30%);

$color-text-maxcontrast: $color-main-text;
$color-text-light: $color-main-text;
$color-text-lighter: $color-main-text;

$color-loading-light: #000;
$color-loading-dark: #ddd;

$color-box-shadow: $color-main-text;

$color-border: lighten($color-main-background, 50%);
$color-border-dark: lighten($color-main-background, 50%);

[class^='icon-'], [class*=' icon-'],
.action,
#appmenu li a,
.menutoggle {
	opacity: 1 !important;
}