Lighten default color slightly for increased contrast

Signed-off-by: Christopher Ng <chrng8@gmail.com>
(cherry picked from commit 1c753c2)

Author: Pytal

apps/theming/css/default.css

@@ -59,21 +59,21 @@
   --image-background-default: url('/core/img/app-background.jpg');
   --color-background-plain: #0082c9;
   --primary-invert-if-bright: no;
-  --color-primary: #00639a;
+  --color-primary: #006aa3;
   --color-primary-default: #0082c9;
   --color-primary-text: #ffffff;
-  --color-primary-hover: #3282ae;
-  --color-primary-light: #e5eff4;
-  --color-primary-light-text: #00273d;
-  --color-primary-light-hover: #dbe4e9;
+  --color-primary-hover: #3287b5;
+  --color-primary-light: #e5f0f5;
+  --color-primary-light-text: #002a41;
+  --color-primary-light-hover: #dbe5ea;
   --color-primary-text-dark: #ededed;
-  --color-primary-element: #00639a;
+  --color-primary-element: #006aa3;
   --color-primary-element-default-hover: #329bd3;
   --color-primary-element-text: #ffffff;
-  --color-primary-element-hover: #3282ae;
-  --color-primary-element-light: #e5eff4;
-  --color-primary-element-light-text: #00273d;
-  --color-primary-element-light-hover: #dbe4e9;
+  --color-primary-element-hover: #3287b5;
+  --color-primary-element-light: #e5f0f5;
+  --color-primary-element-light-text: #002a41;
+  --color-primary-element-light-hover: #dbe5ea;
   --color-primary-element-text-dark: #ededed;
   --gradient-primary-background: linear-gradient(40deg, var(--color-primary) 0%, var(--color-primary-hover) 100%);
 }

apps/theming/lib/Service/BackgroundService.php

@@ -46,7 +46,7 @@ class BackgroundService {
 	// true when the background is bright and need dark icons
 	public const THEMING_MODE_DARK = 'dark';
 	public const DEFAULT_COLOR = '#0082c9';
-	public const DEFAULT_ACCESSIBLE_COLOR = '#00639a';
+	public const DEFAULT_ACCESSIBLE_COLOR = '#006aa3';
 
 	public const SHIPPED_BACKGROUNDS = [
 		'anatoly-mikhaltsov-butterfly-wing-scale.jpg' => [