I just wrote 'Andi is wearing a red scarf and white tie.' and it was not accepted, so even though DiegoJU has said that it is accepted, it seems that it is not, so I have reported it. To me, the indefinite article 'a' could be optional in this sentence.
For me, this is the only audio so far that is currently too fast to decypher on the first try. The "syal merah" part sounds really weird, as if the "syal" part continues then is cut off then starts with "merah".
"Andi is wearing a red scarf and white tie" should be accepted as it is grammatically correct and equally natural to say. I have no idea how many times I've gotten it wrong because of that 'a' in there.