Panos, as you may already know, naval (and army) uniforms were slow to change even after the orders went out for everyone to adopt the new uniforms. There were several reasons for this:
1. Mail was very slow in those days (especially if you were on the "far side of the world").
2. Getting the new uniforms made, shipped and delivered could take months (even years).
3. Reluctance on the part of officers and crew to replace good uniforms with something different.
4. And, I'm sure that there may have been some other reasons that I can't think of ...
The Playmobil blue "Royal Harbour Guard" were probably styled after the French of that period. The flag has a "fleur de lis" and the figure on the far right in set 7587 certainly looks like a French naval officer. And, let us not forget those French moustaches ... 
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All too true Richard!! Communictions were very difficult...Particularly interesting is the notion of reluctance... Many officers might have wore the new uniforms but they surely kept a lot from the old ones as well to wear as accessories...
And probably true that playmobil, after issuing the english redcoats, wanted to produce a french uniform...although hats show a great difference in the time period....
I also think you have issues with this french moustache.....don't you Richard?
