I don't think they're that far along as to be in 'Qantas colours'- particularly given that the paint job is essentially the last step. More like that there are supposed to be two on the production line with the first signs of Qantas colours on them. I don't know about the 787 but I know for the A380, the rudder is in Qantas red whilst the rest of the aircraft is still in it's primer green. I suspect this is what is possibly occurring on the Boeing line. The rumour suggests that there are a couple of 787s there with the foundations set for a Qantas colour scheme. This isn't to say that they can't still re-paint it in J* colours at the final step.