Change the separator to a custom separator color because the system color for dark mode was just too much.

Mac/AppAssets.swift

@@ -257,6 +257,10 @@ struct AppAssets {
 		}
 	}()
 
+	static var timelineSeparatorColor: NSColor = {
+		return NSColor(named: "timelineSeparatorColor")!
+	}()
+	
 	static var timelineStarSelected: RSImage! = {
 		return RSImage(named: "timelineStar")?.tinted(with: .white)
 	}()

Mac/MainWindow/Timeline/TimelineTableRowView.swift

@@ -61,7 +61,7 @@ class TimelineTableRowView : NSTableRowView {
 		separator = NSView()
 		separator!.translatesAutoresizingMaskIntoConstraints = false
 		separator!.wantsLayer = true
-		separator!.layer?.backgroundColor = NSColor.separatorColor.cgColor
+		separator!.layer?.backgroundColor = AppAssets.timelineSeparatorColor.cgColor
 		addSubview(separator!)
 		if #available(macOS 11.0, *) {
 			NSLayoutConstraint.activate([

Mac/Resources/Assets.xcassets/timelineSeparatorColor.colorset/Contents.json

@@ -1,21 +1,16 @@
 {
-  "info" : {
-    "version" : 1,
-    "author" : "xcode"
-  },
   "colors" : [
     {
-      "idiom" : "universal",
       "color" : {
         "color-space" : "gray-gamma-22",
         "components" : {
-          "white" : "0.900",
-          "alpha" : "1.000"
+          "alpha" : "1.000",
+          "white" : "0.900"
         }
-      }
+      },
+      "idiom" : "universal"
     },
     {
-      "idiom" : "universal",
       "appearances" : [
         {
           "appearance" : "luminosity",
@@ -24,8 +19,13 @@
       ],
       "color" : {
         "platform" : "osx",
-        "reference" : "gridColor"
-      }
+        "reference" : "quaternaryLabelColor"
+      },
+      "idiom" : "universal"
     }
-  ]
-}
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}