[gnome-shell-sass] theme: Desaturate system color

[Florian Müllner <fmuellner src gnome org>]

commit 10a710b455bc8e0d49bd8edeb4b2d79efc26422d
Author: Jakub Steiner <jimmac gmail com>
Date:   Fri Jan 8 17:22:45 2021 +0100

    theme: Desaturate system color
    
    - avoid the color tint for the system grey background
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1599>

 _colors.scss               | 1 +
 _high-contrast-colors.scss | 1 +
 widgets/_overview.scss     | 5 ++++-
 3 files changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/_colors.scss b/_colors.scss
index 882c25b..9d8f72f 100644
--- a/_colors.scss
+++ b/_colors.scss
@@ -28,6 +28,7 @@ $osd_borders_color: transparentize(black, 0.3);
 $osd_outer_borders_color: transparentize(white, 0.84);
 
 $shadow_color: if($variant == 'light', rgba(0,0,0,0.1), rgba(0,0,0,0.2));
+$system_bg_color: desaturate(#241f31,100%); //neutralize the HIG color
 
 //insensitive state derived colors
 $insensitive_fg_color: mix($fg_color, $bg_color, 50%);
diff --git a/_high-contrast-colors.scss b/_high-contrast-colors.scss
index 7101793..b34e0b1 100644
--- a/_high-contrast-colors.scss
+++ b/_high-contrast-colors.scss
@@ -26,6 +26,7 @@ $osd_borders_color: rgba(0,0,0, 0.7);
 $osd_outer_borders_color: rgba(255,255,255, 0.1);
 
 $shadow_color: rgba(0,0,0, 0.1);
+$system_bg_color: desaturate(#241f31,100%); //neutralize the HIG color
 
 //insensitive state derived colors
 $insensitive_fg_color: mix($fg_color, $bg_color, 50%);
diff --git a/widgets/_overview.scss b/widgets/_overview.scss
index 18497de..b429bcf 100644
--- a/widgets/_overview.scss
+++ b/widgets/_overview.scss
@@ -2,7 +2,10 @@
 
 #overview {
   spacing: 24px;
-  background-color: transparent;
+}
+
+#overviewGroup {
+  background-color: $system_bg_color;
 }
 
 .overview-controls {