gnome-shell-dark-theme/gnome-shell-sass/_colors.scss

//
// Main color definitions
//
// When color definition differs for dark and light variant, it gets @if-ed depending on $variant

@import '_palette.scss';
@import '_default-colors.scss';


// global colors
$base_color: if($variant == 'light', $light_1, $_base_color_dark);
$bg_color: if($variant == 'light', $_base_color_light, lighten($base_color, 5%));
$fg_color: if($variant == 'light', $_base_color_dark, $light_1);

// OSD elements
$osd_fg_color: $light_1;
$osd_bg_color: lighten($_base_color_dark, 5%);

// system elements (e.g. the overview) that are always dark
$system_base_color: $_base_color_dark;
$system_fg_color: $_base_color_light;

// panel colors
$panel_bg_color: if($variant == 'light', $_base_color_light, $dark_4);
$panel_fg_color: if($variant == 'light', $_base_color_dark, $light_1);

// card elements
$card_bg_color: if($variant == 'light', $light_1, lighten($bg_color, 7%));
$card_shadow_color: if($variant == 'light', transparentize($dark_5, .97), transparent);
$card_shadow_border_color: if($variant == 'light', transparentize($dark_5, .91), transparent);

//
// Derived Colors
//
// colors based on the global defines above

// borders
$borders_color: transparentize($fg_color, $border_opacity);
$outer_borders_color: if($variant == 'light', darken($bg_color, 7%), lighten($bg_color, 5%));

// osd colors
$osd_borders_color: transparentize($osd_fg_color, 0.9);
$osd_outer_borders_color: transparentize($osd_fg_color, 0.98);

// system colors
$system_bg_color: lighten($system_base_color, 5%);
$system_borders_color: transparentize($system_fg_color, .9);
$system_insensitive_fg_color: mix($system_fg_color, $system_bg_color, 50%);
$system_overlay_bg_color: mix($system_base_color, $system_fg_color, 90%); // for non-transparent items, e.g. dash

// insensitive state
$insensitive_fg_color: if($variant == 'light', mix($fg_color, $bg_color, 60%),  mix($fg_color, $bg_color, 50%));
$insensitive_bg_color: mix($bg_color, $base_color, 60%);
$insensitive_borders_color: mix($borders_color, $base_color, 60%);

// checked state
$checked_bg_color: if($variant=='light', darken($bg_color, 7%), lighten($bg_color, 7%));
$checked_fg_color: if($variant=='light', darken($fg_color, 7%), lighten($fg_color, 7%));

// hover state
$hover_bg_color: if($variant=='light', darken($bg_color,9%), lighten($bg_color, 10%));
$hover_fg_color: if($variant=='light', darken($fg_color,9%), lighten($fg_color, 10%));

// active state
$active_bg_color: if($variant=='light', darken($bg_color, 11%), lighten($bg_color, 12%));
$active_fg_color: if($variant=='light', darken($fg_color, 11%), lighten($fg_color, 12%));

// accent colors
$accent_borders_color: if($variant== 'light', st-darken(-st-accent-color, 15%), st-lighten(-st-accent-color, 15%));