To the best of my knowledge, there's no other reason than readability considering these crucial 15 mn prior to the start of a sailboat race for the Skipper where the whole team is excited and busy to get started at its best.
But this is a very unusual color scheme I've never seen on any other vintage yachting watch.
The Skipper range has had a long career being produced up to the mid-80s.
After the Skipperera, Heuer swapped the Carrera case for the Autavia case and the 15mn register color scheme for the more traditional red/white/blue 5mn sector colors as seen in the following Skipper launched somewhere between 1969 and 1970, the appealing detail here to my eyes is the over-sized 15mn register which is also fairly unusual.
Credit : OnTheDash
Heuer also made some others attempts for yachting chronographs layout like this ultra rare dial which has just popped up last week on OnTheDash
credit : Paul Gavin - Heuerworld
As far as I know, this dial is a prototype never launched on the market, the register layout is borrowed from another outstanding Heuer range also linked to the sea, but this another is story.
At the end, I see no other reason for the Skipperera's color scheme than the late 60s flavors where life was easy going, fun and colored. It is to me a tribute to this atmosphere, it brings quite some fun in my passion for vintage chronographs.
Thanks again for your kind words.
L