Follow system theme colorscheme

templates/wezterm/includes/colors.lua.j2

@@ -1,10 +1,35 @@
 -- {{ ansible_managed }}
 
+local wezterm = require 'wezterm'
+
+-- wezterm.gui is not available to the mux server, so take care to
+-- do something reasonable when this config is evaluated by the mux
+local function get_appearance()
+  if wezterm.gui then
+    return wezterm.gui.get_appearance()
+  end
+  return 'Dark'
+end
+
+local function scheme_for_appearance(appearance)
+  if appearance:find 'Dark' then
+    return 'Dark'
+  else
+    return 'Light'
+  end
+end
+
 return {
-  colors = {
-    -- The default text color
-    foreground = 'black',
-    -- The default background color
-    background = 'white'
-  }
+  color_schemes = {
+    ['Dark'] = {
+      background = 'rgb(41, 46, 50)',
+      foreground = 'white'
+    },
+    ['Light'] = {
+      background = 'white',
+      foreground = 'black'
+    },
+  },
+
+  color_scheme = scheme_for_appearance(get_appearance()),
 }