diff --git a/Timer/Assets.xcassets/Contents.json b/Timer/Assets.xcassets/Contents.json
index da4a164..73c0059 100644
--- a/Timer/Assets.xcassets/Contents.json
+++ b/Timer/Assets.xcassets/Contents.json
@@ -1,6 +1,6 @@
 {
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
\ No newline at end of file
+}
diff --git a/Timer/Assets.xcassets/Labels/Contents.json b/Timer/Assets.xcassets/Labels/Contents.json
new file mode 100644
index 0000000..73c0059
--- /dev/null
+++ b/Timer/Assets.xcassets/Labels/Contents.json
@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}
diff --git a/Timer/Assets.xcassets/Labels/minutes-label.colorset/Contents.json b/Timer/Assets.xcassets/Labels/minutes-label.colorset/Contents.json
new file mode 100644
index 0000000..01992aa
--- /dev/null
+++ b/Timer/Assets.xcassets/Labels/minutes-label.colorset/Contents.json
@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.271",
+          "green" : "0.255",
+          "red" : "0.235"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.645",
+          "green" : "0.645",
+          "red" : "0.645"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}
diff --git a/Timer/Assets.xcassets/Labels/seconds-label.colorset/Contents.json b/Timer/Assets.xcassets/Labels/seconds-label.colorset/Contents.json
new file mode 100644
index 0000000..ac34b3b
--- /dev/null
+++ b/Timer/Assets.xcassets/Labels/seconds-label.colorset/Contents.json
@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.686",
+          "green" : "0.667",
+          "red" : "0.635"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.533",
+          "green" : "0.520",
+          "red" : "0.497"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}
diff --git a/Timer/Assets.xcassets/Labels/timer-label.colorset/Contents.json b/Timer/Assets.xcassets/Labels/timer-label.colorset/Contents.json
new file mode 100644
index 0000000..619920a
--- /dev/null
+++ b/Timer/Assets.xcassets/Labels/timer-label.colorset/Contents.json
@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.012",
+          "green" : "0.141",
+          "red" : "0.749"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.485",
+          "green" : "0.626",
+          "red" : "0.745"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}
diff --git a/Timer/Assets.xcassets/clock-highlighted.imageset/Contents.json b/Timer/Assets.xcassets/clock-highlighted.imageset/Contents.json
index 003e9e8..35fa749 100644
--- a/Timer/Assets.xcassets/clock-highlighted.imageset/Contents.json
+++ b/Timer/Assets.xcassets/clock-highlighted.imageset/Contents.json
@@ -1,23 +1,56 @@
 {
   "images" : [
     {
-      "idiom" : "universal",
       "filename" : "clock-highlighted.png",
+      "idiom" : "universal",
       "scale" : "1x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-highlighted-1.png",
       "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
       "filename" : "clock-highlighted@2x.png",
+      "idiom" : "universal",
       "scale" : "2x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-highlighted@2x-1.png",
       "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
       "filename" : "clock-highlighted@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-highlighted@3x-1.png",
+      "idiom" : "universal",
       "scale" : "3x"
     }
   ],
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
\ No newline at end of file
+}
diff --git a/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted-1.png b/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted-1.png
new file mode 100644
index 0000000..7a46d26
Binary files /dev/null and b/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted-1.png differ
diff --git a/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted@2x-1.png b/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted@2x-1.png
new file mode 100644
index 0000000..f8c599a
Binary files /dev/null and b/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted@2x-1.png differ
diff --git a/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted@3x-1.png b/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted@3x-1.png
new file mode 100644
index 0000000..bca5f07
Binary files /dev/null and b/Timer/Assets.xcassets/clock-highlighted.imageset/clock-highlighted@3x-1.png differ
diff --git a/Timer/Assets.xcassets/clock-unfocus.imageset/Contents.json b/Timer/Assets.xcassets/clock-unfocus.imageset/Contents.json
index dacfe57..b134d9f 100644
--- a/Timer/Assets.xcassets/clock-unfocus.imageset/Contents.json
+++ b/Timer/Assets.xcassets/clock-unfocus.imageset/Contents.json
@@ -1,23 +1,56 @@
 {
   "images" : [
     {
-      "idiom" : "universal",
       "filename" : "clock-unfocus.png",
+      "idiom" : "universal",
       "scale" : "1x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-unfocus-dark.png",
       "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
       "filename" : "clock-unfocus@2x.png",
+      "idiom" : "universal",
       "scale" : "2x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-unfocus-dark@2x.png",
       "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
       "filename" : "clock-unfocus@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-unfocus-dark@3x.png",
+      "idiom" : "universal",
       "scale" : "3x"
     }
   ],
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
\ No newline at end of file
+}
diff --git a/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark.png b/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark.png
new file mode 100644
index 0000000..cef9614
Binary files /dev/null and b/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark.png differ
diff --git a/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark@2x.png b/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark@2x.png
new file mode 100644
index 0000000..6158387
Binary files /dev/null and b/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark@2x.png differ
diff --git a/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark@3x.png b/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark@3x.png
new file mode 100644
index 0000000..ec17de5
Binary files /dev/null and b/Timer/Assets.xcassets/clock-unfocus.imageset/clock-unfocus-dark@3x.png differ
diff --git a/Timer/Assets.xcassets/clock.imageset/Contents.json b/Timer/Assets.xcassets/clock.imageset/Contents.json
index f88c080..16db03e 100644
--- a/Timer/Assets.xcassets/clock.imageset/Contents.json
+++ b/Timer/Assets.xcassets/clock.imageset/Contents.json
@@ -1,23 +1,56 @@
 {
   "images" : [
     {
-      "idiom" : "universal",
       "filename" : "clock.png",
+      "idiom" : "universal",
       "scale" : "1x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-dark.png",
       "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
       "filename" : "clock@2x.png",
+      "idiom" : "universal",
       "scale" : "2x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-dark@2x.png",
       "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
       "filename" : "clock@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "clock-dark@3x.png",
+      "idiom" : "universal",
       "scale" : "3x"
     }
   ],
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
\ No newline at end of file
+}
diff --git a/Timer/Assets.xcassets/clock.imageset/clock-dark.png b/Timer/Assets.xcassets/clock.imageset/clock-dark.png
new file mode 100644
index 0000000..e9ddcbe
Binary files /dev/null and b/Timer/Assets.xcassets/clock.imageset/clock-dark.png differ
diff --git a/Timer/Assets.xcassets/clock.imageset/clock-dark@2x.png b/Timer/Assets.xcassets/clock.imageset/clock-dark@2x.png
new file mode 100644
index 0000000..7f495c0
Binary files /dev/null and b/Timer/Assets.xcassets/clock.imageset/clock-dark@2x.png differ
diff --git a/Timer/Assets.xcassets/clock.imageset/clock-dark@3x.png b/Timer/Assets.xcassets/clock.imageset/clock-dark@3x.png
new file mode 100644
index 0000000..293a08d
Binary files /dev/null and b/Timer/Assets.xcassets/clock.imageset/clock-dark@3x.png differ
diff --git a/Timer/Assets.xcassets/icon-pause.imageset/Contents.json b/Timer/Assets.xcassets/icon-pause.imageset/Contents.json
index cab3d76..680e784 100644
--- a/Timer/Assets.xcassets/icon-pause.imageset/Contents.json
+++ b/Timer/Assets.xcassets/icon-pause.imageset/Contents.json
@@ -1,23 +1,56 @@
 {
   "images" : [
     {
-      "idiom" : "universal",
       "filename" : "icon-pause.png",
+      "idiom" : "universal",
       "scale" : "1x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "icon-pause-dark.png",
       "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
       "filename" : "icon-pause@2x.png",
+      "idiom" : "universal",
       "scale" : "2x"
     },
     {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "icon-pause-dark@2x.png",
       "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
       "filename" : "icon-pause@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "filename" : "icon-pause-dark@3x.png",
+      "idiom" : "universal",
       "scale" : "3x"
     }
   ],
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
\ No newline at end of file
+}
diff --git a/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark.png b/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark.png
new file mode 100644
index 0000000..7963b51
Binary files /dev/null and b/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark.png differ
diff --git a/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark@2x.png b/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark@2x.png
new file mode 100644
index 0000000..fc87948
Binary files /dev/null and b/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark@2x.png differ
diff --git a/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark@3x.png b/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark@3x.png
new file mode 100644
index 0000000..fb452ee
Binary files /dev/null and b/Timer/Assets.xcassets/icon-pause.imageset/icon-pause-dark@3x.png differ
diff --git a/Timer/MVClockView.swift b/Timer/MVClockView.swift
index 1f27d8e..46c8efb 100644
--- a/Timer/MVClockView.swift
+++ b/Timer/MVClockView.swift
@@ -97,14 +97,22 @@ class MVClockView: NSControl {
     timerTimeLabel = MVLabel(frame: NSRect(x: 0, y: 94, width: 150, height: 20))
     timerTimeLabel.font = NSFont.systemFont(ofSize: timerTimeLabelFontSize, weight: .medium)
     timerTimeLabel.alignment = NSTextAlignment.center
-    timerTimeLabel.textColor = NSColor(srgbRed: 0.749, green: 0.1412, blue: 0.0118, alpha: 1.0)
+    if #available(macOS 10.13, *) {
+        timerTimeLabel.textColor = NSColor(named: "timer-label")
+    } else {
+        timerTimeLabel.textColor = NSColor(srgbRed: 0.749, green: 0.1412, blue: 0.0118, alpha: 1.0)
+    }
     self.addSubview(timerTimeLabel)
 
     minutesLabel = MVLabel(frame: NSRect(x: 0, y: 57, width: 150, height: 30))
     minutesLabel.string = ""
     minutesLabel.font = NSFont.monospacedDigitSystemFont(ofSize: 35, weight: .medium)
     minutesLabel.alignment = NSTextAlignment.center
-    minutesLabel.textColor = NSColor(srgbRed: 0.2353, green: 0.2549, blue: 0.2706, alpha: 1.0)
+    if #available(macOS 10.13, *) {
+        minutesLabel.textColor = NSColor(named: "minutes-label")
+    } else {
+        minutesLabel.textColor = NSColor(srgbRed: 0.2353, green: 0.2549, blue: 0.2706, alpha: 1.0)
+    }
     self.addSubview(minutesLabel)
 
     let minutesLabelSuffix = "'"
@@ -122,7 +130,11 @@ class MVClockView: NSControl {
     secondsLabel = MVLabel(frame: NSRect(x: 0, y: 38, width: 150, height: 20))
     secondsLabel.font = NSFont.monospacedDigitSystemFont(ofSize: 15, weight: .regular)
     secondsLabel.alignment = NSTextAlignment.center
-    secondsLabel.textColor = NSColor(srgbRed: 0.6353, green: 0.6667, blue: 0.6863, alpha: 1.0)
+    if #available(OSX 10.13, *) {
+        secondsLabel.textColor = NSColor(named: "seconds-label")
+    } else {
+        secondsLabel.textColor = NSColor(srgbRed: 0.6353, green: 0.6667, blue: 0.6863, alpha: 1.0)
+    }
     self.addSubview(secondsLabel)
 
     let secondsLabelSuffix = "'"