All Midas and Red Devils start out as barred, while the true barred Midas and RD will stay barred throughout their whole life and the colored ones will slowly changed from barred to whatever colors as they get older. The ones from local petshops will surely change to colored specimens unless it's a reputable shop and they're marked as barred Midas.
On a side note, not quite sure how Petsmart does it but their Midas/RD turned colored at a very early age/size.