Well, here I am, answering...myself! Sifting through a couple of sites, I found two entries by Dan-San Abbott on the subject. DSA writes:
A. "The tape colors was (sic) to (my opinion) to identify the manufacture. The "salmon pink" tapes were only used by the Albatros and the light blue was only used by OAW. Albatros or OAW
would not have mixed tape colors. There are several points of the contention." (DSA, Aerodrome, 8 Mar 2010).
B. "The Albatros Werke used salmon pink tape on Alb.D.V/D.Va rib tapes. To my knowledge, I do not know of any other German aircraft builder that used pink tapes of any shade for rib tapes." (DSA, Great War Forum, 17 Nov 2004). (Note: I don't know the clear meaning of the statement, "There are several points of the contention.")
I fully understand that, at this late date, no one will really know for sure. The best we (or "I") can do is to fall back on the Law of Probabilities. Right now, it appears "probable" that the tapes on 4545/17 were Salmon Pink.
And once we have this definitely confirmed, we'll sort out the colour of Lothar's triplane's upper wing...! 
Dear old Dan-San! How I miss him.
I know he unearthed many colouring and marking details but he had a habit of stating things as being so without quoting his reasoning or sources. At least in statement 'A' the words "in my opinion" appear.
In Dan-San's
opinion the tapes were used to identify the manufacturer.
In the
opinion of others, the differentially coloured blue and pink tapes might ORIGINALLY have been intended to tone in with the top and bottom lozenge colours (blue upper, pink lower), but this was quickly found to be too time-consuming (application of a single tape wrapping around the leading edge and covering the rib locations top and bottom was much quicker) and the possibility of holding up production due to a shortage of the right colour of rib tape was seen as undesirable and unnecessary - particularly given the negligible impact of blue or pink tapes on the camouflage effect of the printed fabric, so rib tapes of whatever colour available were applied by either factory. NOTE I have NO evidence that this is true - it is an explanation of sorts and probably just as valid as any other until documentary evidence is unearthed - or if it has already been discovered, produced.
There is a view that the different rib tape colours can be discerned from period black and white photographs, thus a correlation between the perceived rib colour and the serial number has been made and the link of a particular colour to a specific manufacturer established. This may be the origin of Dan-San's opinion - I don't know.
It might just be possible to correlate the grey-shade of a rib tape to the grey-shade of a particular lozenge, whose colour is known from its shape and position and from there make a reasonable stab at saying the rib colour was blue or pink but that depends on the photograph being of good quality and the lozenges clearly identifiable. While photos of such quality do exist, there aren't many of them. At one point Dan-San was making pronouncements of colours in black and white photos based entirely on their grey-scale interpretation - he even was quoting Methuen colour references at one point. This approach was seen and proved to be false and he seemed to stop making such pronouncements after a while.
I am not looking to start a war of words here or to damage the memory and research credentials of a man I regarded as a friend and who did an enormous amount to aid our understanding of WWI aviation history and colours and markings. I just would like
someone to explain these strictures about rib tape colours stating their sources and reasoning, so that we can verify their claims, or otherwise.
