Update Nord Palette for better readability (#4517)

core/palettes/Nord.tid

@@ -63,8 +63,8 @@ primary: #5E81AC
 select-tag-background: #3b4252
 select-tag-foreground: <<colour foreground>>
 sidebar-button-foreground: <<colour foreground>>
-sidebar-controls-foreground-hover: #4C566A
-sidebar-controls-foreground: #3B4252
+sidebar-controls-foreground-hover: #D8DEE9
+sidebar-controls-foreground: #4C566A
 sidebar-foreground-shadow: transparent
 sidebar-foreground: #D8DEE9
 sidebar-muted-foreground-hover: #4C566A