Added some accent color for #53

CSS/themes/nzbhydra2/aquamarine.css

@@ -18,4 +18,5 @@
   --modal-bg-color: radial-gradient(ellipse at top, #47918a 0%, #0b3161 100%) center center/cover no-repeat fixed;
   --default-button-color: #009688;
   --default-button-color-hover:  radial-gradient(ellipse at center, #5066e0 0%, #01ccb9 100%) center center/cover no-repeat fixed;
+  --accent-color: #118074;
 }

CSS/themes/nzbhydra2/dark.css

@@ -18,4 +18,5 @@
   --modal-bg-color: radial-gradient(circle , #3a3a3a, #2d2d2d, #202020, #141414, #000000) center center/cover no-repeat fixed;
   --default-button-color: #cc7b19;
   --default-button-color-hover: #e59029;
+  --accent-color: #cc7b19;
   }

CSS/themes/nzbhydra2/hotline.css

@@ -18,4 +18,5 @@
   --modal-bg-color: radial-gradient(ellipse at top, #F44336 0%, #0b3161 100%) center center/cover no-repeat fixed;
   --default-button-color: radial-gradient(ellipse at center, #F44336 0%, #3F51B5 100%) center center/cover no-repeat fixed;
   --default-button-color-hover: radial-gradient(ellipse at center, #fb6054 0%, #5269e6 100%) center center/cover no-repeat fixed;
+  --accent-color: var(--default-button-color);
 }

CSS/themes/nzbhydra2/nzbhydra-base.css

@@ -29,10 +29,10 @@
     background-color: rgba(255, 255, 255, 0.08);
 }
 .growl-container>.alert-info.icon {
-    background: var(--modal-bg-color);
+    background: var(--accent-color);
 }
 .alert-info {
-    background: var(--modal-bg-color);
+    background: var(--accent-color);
     border-color: transparent;
     color: #fff;
     box-shadow: 0 8px 16px 0 rgba(0,0,0,0.2), 0 6px 20px 0 rgba(0,0,0,0.19);

CSS/themes/nzbhydra2/plex.css

@@ -18,4 +18,5 @@
   --modal-bg-color: url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/blur-noise.png"), url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/preset-dark2.png") center center/cover no-repeat fixed;
   --default-button-color: #cc7b19;
   --default-button-color-hover: #e59029;
+  --accent-color: #cc7b19;
 }

CSS/themes/nzbhydra2/space-gray.css

@@ -18,4 +18,5 @@
   --modal-bg-color: radial-gradient( ellipse at top,  rgba(87,108,117,1) 0%, rgba(37,50,55,1) 100.2% ) center center/cover no-repeat fixed;
   --default-button-color: #607D8B;
   --default-button-color-hover: #81a6b7;
+  --accent-color: #7598a9;
 }