diff --git a/static/atom.less b/static/atom.less
index 695292b6d..8a5075d64 100644
--- a/static/atom.less
+++ b/static/atom.less
@@ -1,5 +1,9 @@
-// Import from the theme's variables with a fallback to /static/variables/ui-variables.less
+// Import from the syntax theme's variables with a fallback to ./variables/syntax-variables.less
+@import "syntax-variables";
+
+// Import from the ui theme's variables with a fallback to ./variables/ui-variables.less
 @import "ui-variables";
+
 @import "octicon-utf-codes";
 @import "octicon-mixins";
 
@@ -19,5 +23,6 @@
 @import "markdown";
 @import "editor";
 @import "select-list";
+@import "syntax";
 @import "utilities";
 @import "octicons";
diff --git a/static/syntax.less b/static/syntax.less
new file mode 100644
index 000000000..ffae437bd
--- /dev/null
+++ b/static/syntax.less
@@ -0,0 +1,21 @@
+@import "syntax-variables";
+
+.editor {
+  .lines {
+    .markup {
+      &.git-commit {
+        &.changed {
+          color: @syntax-color-modified;
+        }
+
+        &.deleted {
+          color: @syntax-color-removed;
+        }
+
+        &.inserted {
+          color: @syntax-color-added;
+        }
+      }
+    }
+  }
+}
diff --git a/static/variables/syntax-variables.less b/static/variables/syntax-variables.less
new file mode 100644
index 000000000..fb6895405
--- /dev/null
+++ b/static/variables/syntax-variables.less
@@ -0,0 +1,8 @@
+// This file has fallback variables. It specifies the syntax variables that
+// themes must implement.
+
+// Colors
+
+@syntax-color-added: #5293d8;
+@syntax-color-modified: #f78a46;
+@syntax-color-removed: #c00;