docs: update css.md

contributing/css.md

@@ -9,7 +9,9 @@ the official website: <https://sass-lang.com/install>
 Open your terminal, and navigate to CodeIgniter's root folder. To
 generate the CSS file, use the following command:
 
-`sass --no-source-map admin/css/debug-toolbar/toolbar.scss system/Debug/Toolbar/Views/toolbar.css`
+```console
+sass --no-source-map admin/css/debug-toolbar/toolbar.scss system/Debug/Toolbar/Views/toolbar.css`
+```
 
 Details:
 - `--no-source-map` is an option which prevents sourcemap files from being generated
@@ -18,23 +20,4 @@ Details:
 
 ## Color scheme
 
-**Themes**
-
-Dark: `#252525` / `rgb(37, 37, 37)`
-Light: `#FFFFFF` / `rgb(255, 255, 255)`
-
-**Glossy colors**
-
-Blue: `#5BC0DE` / `rgb(91, 192, 222)`
-Gray: `#434343` / `rgb(67, 67, 67)`
-Green: `#9ACE25` / `rgb(154, 206, 37)`
-Orange: `#DD8615` / `rgb(221, 134, 21)`
-Red: `#DD4814` / `rgb(221, 72, 20)`
-
-**Matt colors**
-
-Blue: `#D8EAF0` / `rgb(216, 234, 240)`
-Gray: `#DFDFDF` / `rgb(223, 223, 223)`
-Green: `#DFF0D8` / `rgb(223, 240, 216)`
-Orange: `#FDC894` / `rgb(253, 200, 148)`
-Red: `#EF9090` / `rgb(239, 144, 144)`
+See [_graphic-charter.scss](../admin/css/debug-toolbar/_graphic-charter.scss).