QANTAS "Dreaming" aircraft slower.
According to a BBC report on that television`s "Flight Track" programme, a QANTAS F/A - Ken D_ _son, emailed BBC to advise the station that the aircraft painted in Aboriginal colours (presumably one of the "Dreaming" series - Wunala Dreaming · Nalanji Dreaming ) adds an extra 30 minutes to the flight time from Australia to Bangkok, in addition to the penalties owing to the extra weight (because of the paint scheme).
Thank you F/A Ken.