diff -r 5ef3bfef0bff -r 48458e099b05 cms/app-client/app/components/visu-chrono-year.js
--- a/cms/app-client/app/components/visu-chrono-year.js	Sun Nov 06 03:44:16 2016 +0100
+++ b/cms/app-client/app/components/visu-chrono-year.js	Tue Nov 08 01:22:56 2016 +0100
@@ -24,7 +24,7 @@
         if(this.get('isDisabled')) {
             return false;
         }
-        return this.get('colors').getPerceptiveLuminance(this.get('backgroundColor')) >= 0.5;
+        return this.get('colors').getPerceptiveLuminance(backgroundColor) >= 0.5;
     }),
 
     backgroundColor: Ember.computed('count', 'maxCount', 'minCount', function() {