Painting your front door blue could add £4,000 to your property value, but brown could decrease it by £700

(Picture: Getty Images)They say never judge a book by its cover, but it turns out that quite a few people judge properties by the colour of their front doors.Research by property company Sellhousefast.uk found that something as simples as changing the colour of your front door can affect its value by up to £4,000.The company analysed over 1,000 UK properties on Zoopla with three bedrooms and a garden, and calculated the average price as £275,000.10 properties of each d