diff --git a/src/services/theme_data/theme_data.service.js b/src/services/theme_data/theme_data.service.js
index 4d7e4f67..dd87e3cf 100644
--- a/src/services/theme_data/theme_data.service.js
+++ b/src/services/theme_data/theme_data.service.js
@@ -384,12 +384,13 @@ export const getColors = (sourceColors, sourceOpacity) => SLOT_ORDERED.reduce(({
             : (OPACITIES[opacitySlot] || {}).defaultValue
         )
       }
-      if (Number.isNaN(outputColor.a)) {
-        outputColor.a = 1
-      }
     }
   }
 
+  if (Number.isNaN(outputColor.a) || outputColor.a === undefined) {
+    outputColor.a = 1
+  }
+
   if (opacitySlot) {
     return {
       colors: { ...colors, [key]: outputColor },