I'm having a hard time to understand why there are so many people that mix up "la" and "una" because of the voice. Apart from some details here and there (it always pronounces "perché" as if it meant "because" instead of "why") the diction seems pretty legit to me, and I'm writing this on September 24, 2014. Maybe you guys are talking about a voice that was changed recently? As a Spaniard, I just hear the normal liaisons (HOU-na camicia) between vowels that happen both in Italian and Spanish at normal talking speed. The "u" sound is there, and it wouldn't be there if the voice just said "ho la camicia" (HO la camicia).
Some colours (not all, and I cant tell which one does) will change its ending according to what item it is connected to. Colorata is connected to an object that is feminine and singular. Colorati is connected to an object that is feminine and plural
I hope I made it bit more clear and it was useful for you
"I have a colourful shirt" should be accepted. U.S. English may be an American company's default, but Commonwealth spelling is not incorrect.
Did you also leave a flag on the answer itself?
Moderators, there really needs to be a pinned post at the top of every discussion that notes what the chat here can and cannot do. Here we can confirm or deny correct answers, but changes to the app can really only come from flagging the incorrect response (or correct one, if you were "incorrectly" given credit...)
The pin should say welcome, and "please scan the answers already written here before adding a new post!" A simple reply or like to a previously given answer can sometimes make all the difference. But then this needs to be written at the top of EVERY single discussion!