🐛 bug fix: color fields were converted from hex to dec values

Added this two color fields to $colorFields:
- design_button_font_color
- design_button_font_color_light

CRM/TwingleCampaign/BAO/TwingleProject.php

@@ -36,6 +36,8 @@ class CRM_TwingleCampaign_BAO_TwingleProject extends Campaign {
     'design_background_color',
     'design_primary_color',
     'design_font_color',
+    'design_button_font_color',
+    'design_button_font_color_light',
   ];
 
   /**