It needs more colours on the aircraft, to much white!

any suggestions? i’d love to read them.
by the way, I`m posting two A330 pictures, an (imaginary) old c/s (usually seen on the A310 in the 90s), and the actual c/s .
Regards.

well well well….. it’s getting confusing here, if it’s not the Pressurization outflow valve cause a 747 has actually two valves ( like skycruiser said), then what is it then ?? :confused:

MINIDOH, I think RIPConcorde has the answer, it’s the Pressurization outflow valve , I personally don’t think it’s coming from another aircraft cause normally in that case you’ll see at least two contrails not only one.
Regards.

I thought it’s an APU when i first looked at the pic, but yeah you’re right, not at that altitude !!