They are all transactions (involving a buyer and a seller) ... but they are defined on whether they are committed on the ask or on the bid.
A transaction at the bid implies that neither the buyer nor the seller thought the stock was worth the ask at the time. That is why they are labelled red (indicating the negative sentiment).
I kindly challenge you to explain your logic with that one. Shares don't just come out of the air when you make a purchase, they are being supplied by another living being.