diff --git a/pixelegg/css/pixelegg.css b/pixelegg/css/pixelegg.css
index 108b4a4e75..a3702bd354 100644
--- a/pixelegg/css/pixelegg.css
+++ b/pixelegg/css/pixelegg.css
@@ -242,6 +242,30 @@
     background-color: #ffc200;
     border-color: #bf9d30;
   }
+  .et2_gantt .gantt_task_link .gantt_line_wrapper div {
+    background-color: green;
+  }
+  .et2_gantt .gantt_task_link .gantt_link_arrow_left {
+    border-right-color: green;
+  }
+  .et2_gantt .gantt_task_link .gantt_link_arrow_right {
+    border-left-color: green;
+  }
+  .et2_gantt .gantt_task_link:hover .gantt_line_wrapper div {
+    box-shadow: 0 0 5px 0 green;
+  }
+  .et2_gantt .gantt_task_link.invalid_constraint .gantt_line_wrapper div {
+    background-color: #ae1d00;
+  }
+  .et2_gantt .gantt_task_link.invalid_constraint .gantt_link_arrow_left {
+    border-right-color: #ae1d00;
+  }
+  .et2_gantt .gantt_task_link.invalid_constraint .gantt_link_arrow_right {
+    border-left-color: #ae1d00;
+  }
+  .et2_gantt .gantt_task_link.invalid_constraint:hover .gantt_line_wrapper div {
+    box-shadow: 0 0 5px 0 #ae1d00;
+  }
   /*Link to / Selector Widget*/
   .et2_link_to .et2_button_icon {
     /*.background_color_10_gray;*/
diff --git a/pixelegg/less/etemplate2.less b/pixelegg/less/etemplate2.less
index 083e274695..d8c26cc701 100755
--- a/pixelegg/less/etemplate2.less
+++ b/pixelegg/less/etemplate2.less
@@ -201,6 +201,43 @@ div.et2_file input.et2_file_upload{
 		background-color: @egw_color_1;
 		border-color: @egw_color_1_b;
 	}
+	.gantt_task_link
+	{
+		.gantt_line_wrapper div
+		{
+			background-color: green;
+		}
+		.gantt_link_arrow_left
+		{
+			border-right-color:  green;
+		}
+		.gantt_link_arrow_right
+		{
+			border-left-color:  green;
+		}
+		&:hover .gantt_line_wrapper div {
+			box-shadow: 0 0 5px 0 green;
+		}
+	}
+	
+	.gantt_task_link.invalid_constraint {
+		.gantt_line_wrapper div
+		{
+			background-color: @color_error;
+		}
+		.gantt_link_arrow_left
+		{
+			border-right-color:  @color_error;
+		}
+		.gantt_link_arrow_right
+		{
+			border-left-color:  @color_error;
+		}
+		&:hover .gantt_line_wrapper div
+		{
+			box-shadow: 0 0 5px 0 @color_error;
+		}
+	}
 }
 
 /*Link to / Selector Widget*/