diff --git a/packages/grafana-ui/src/components/ColorPicker/_ColorPicker.scss b/packages/grafana-ui/src/components/ColorPicker/_ColorPicker.scss
index 2d2dbb6896d..46eed5f7ff1 100644
--- a/packages/grafana-ui/src/components/ColorPicker/_ColorPicker.scss
+++ b/packages/grafana-ui/src/components/ColorPicker/_ColorPicker.scss
@@ -199,6 +199,7 @@ $arrowSize: 15px;
   margin: 0;
   float: left;
   z-index: 0;
+  background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAAMCAIAAADZF8uwAAAAGUlEQVQYV2M4gwH+YwCGIasIUwhT25BVBADtzYNYrHvv4gAAAABJRU5ErkJggg==);
 }
 
 .sp-preview-inner,
diff --git a/public/app/plugins/panel/graph/threshold_manager.ts b/public/app/plugins/panel/graph/threshold_manager.ts
index ef9feb80a5b..f0bc7d62499 100644
--- a/public/app/plugins/panel/graph/threshold_manager.ts
+++ b/public/app/plugins/panel/graph/threshold_manager.ts
@@ -198,6 +198,7 @@ export class ThresholdManager {
       }
 
       let fillColor, lineColor;
+
       switch (threshold.colorMode) {
         case 'critical': {
           fillColor = 'rgba(234, 112, 112, 0.12)';
@@ -215,6 +216,12 @@ export class ThresholdManager {
           break;
         }
         case 'custom': {
+          if (!threshold.fillColor) {
+            threshold.fillColor = 'rgba(255, 255, 255, 1)';
+          }
+          if (!threshold.lineColor) {
+            threshold.lineColor = 'rgba(255, 255, 255, 0)';
+          }
           fillColor = threshold.fillColor;
           lineColor = threshold.lineColor;
           break;