[gimp] themes: have the "extreme" CSS colors a bit less extreme.

[Jehan <jehanp src gnome org>]

commit 91ec8a34f3fd66fa8ab0487c1cb3f304745993db
Author: Jehan <jehan girinstud io>
Date:   Thu Sep 29 17:15:43 2022 +0200

    themes: have the "extreme" CSS colors a bit less extreme.
    
    We had some concept of slightly more extreme theme colors (i.e. darker in dark
    themes) to color differently in some widget-in-widget cases.
    
    For instance, we use this in the treeview list to separate it better from nearby
    interface. But this extreme dark background may have been a bit "too dark", as
    reported by Jacob. The goal is for this list to stand out, but maybe it was
    standing out too much. Hopefully it's better now.
    
    As a side change, I also add some borders to the top icon header (with "eye" and
    "lock" icons) just above the list. I think it better explain the separation.

 themes/Default/common.css    | 5 +++++
 themes/Default/gimp-dark.css | 6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)
---
diff --git a/themes/Default/common.css b/themes/Default/common.css
index a1e5300fc2..ca6155f8a8 100644
--- a/themes/Default/common.css
+++ b/themes/Default/common.css
@@ -47,6 +47,11 @@
   color: @bg-color;
 }
 
+.view header button {
+  background-color: @bg-color;
+  border: 1px solid @stronger-border-color;
+}
+
 /* The main image window before it has an image in it,
  * and the buttonbar along the bottoms of dialogs.
  * Foreground color here is the text color, not the Wilber color.
diff --git a/themes/Default/gimp-dark.css b/themes/Default/gimp-dark.css
index c6a7f345f1..cce30263d1 100644
--- a/themes/Default/gimp-dark.css
+++ b/themes/Default/gimp-dark.css
@@ -39,12 +39,12 @@
 
 /* Background color more extreme in the theme tendency, i.e. darker on a
  * dark theme, ligther on a light theme. */
-@define-color extreme-bg-color       rgb(5,5,5);
+@define-color extreme-bg-color       rgb(20,20,20);
 /* Color for a selected item to "stick out" when @extreme-bg-color is
  * used. It will usually be darker than @bg-color on a light theme,
- * ligher on a dark theme.
+ * lighter on a dark theme.
  */
-@define-color extreme-selected-color rgb(35,35,35);
+@define-color extreme-selected-color rgb(40,40,40);
 
 /********* Variants for border colors *********/