diff --git a/app/helpers/uprn_address_spike_helper.rb b/app/helpers/uprn_address_spike_helper.rb
index cf521b30f..786ee3cbb 100644
--- a/app/helpers/uprn_address_spike_helper.rb
+++ b/app/helpers/uprn_address_spike_helper.rb
@@ -2,7 +2,9 @@
 
 module UprnAddressSpikeHelper
   def match_colour(match)
-    if match >= 0.8
+    if match == 1
+      "purple"
+    elsif match >= 0.8
       "green"
     elsif match >= 0.7
       "orange"