I understand the Continental Army during the Revolution was supplied haphazardly, at best, but why have troops in historical attire today wear the colors of the hated British regulars? Why not blue and buff, as the Continental line wore?
A common conceit in old-time uniforms was to reverse colors. Men wear black-and-white, officers wear white-and-black, that sort of thing.
The army wore blue with red highlights, the bandsmen wore red with blue highlights. Or so I have been told.
Long tradition, apparently, that the band would wear contrasting colors from those of the line. So if recreating the Old Guard as of the creation of the Army, you would have had the line in blue and the musicians in red.
To this day, similarly, the US Marine Band and Drum and Bugle corps, when on full all-out dress events, wear red instead of blue tunics. And check out that Drum Major.
Straight from Changing the Guard at Buckingham Palace. I had no idea our American cousins sported military bearskins.
To elaborate on the OP, a more complete pic of what the US Army Old Guard Fife & Drum Corps look like on display. Notice the Drum Major’s left-handed, palm-forward hand salute.
And yes, yet another hairy hat. AFAIK it’s only the DM’s who get the big furry headgear in the US military.
Not just military, it’s quite common at the college level and even in some of the better high schools. Interestlying enough, I’ve heard several Brit’s comment (while drooling)about our use of young girls as cheerleaders and have wondered why they haven’t adopted the institution.
An easy answer is that it was so the commanders could find the musicians in the days when orders were passes on by drum beats and bugle calls. Musicians wore uniforms that were the reverse of the uniforms worn by the rank and file. Thus in the British service if the regiment wore a red coat with yellow trim then the drummers, buglers, fifes wore a yellow coat with red trim. In the Napoleonic army the musicians wore a distinctive uniform with stripes all over it. In the American service, up through the War of 1812 the rank and file wore a blue coat with red trim and musicians wore the reverse. The idea was that when, for instance, a regimental commander wanted his double ranked line of battle to swing 90 degrees to the right he could not just start shouting. His battle line might be one hundred yards long and there was a lot of noise going on. What he had to do was to find a drummer or a bugler and tell the musician to play the appropriate tune conveying the commanders wishes preceded by another tune that said whether it was supposed to be done by the whole outfit or just part of the formation. It was critical that the commander be able to find his musicians fast. The bright and different uniform facilitated that.
By the same token in the cavalry the musicians rode different colored horses than the rest of their company, typically grey (white) horses. Generally the adjutant, another guy the commander would want to find quickly, rode a grey horse, too.
Band uniforms got lots of strange stuff. Most European bandsmen still wear wings.
Google Images. It’s a beautiful thing.
Drum majors for the other U.S. armed forces branches…
Army (bearskin): Regimental Drum Major Association Home Page
Navy (bearskin): Regimental Drum Major Association Home Page
and http://www.navyband.navy.mil/Photos/Portraits/MUCMJBrownDM2.jpg
Air Force (no bearskin): http://www.rvsb.org/teleky.jpg
Coast Guard (ditto): http://lh3.ggpht.com/__bOdslk79dc/SDhiFWwB_1I/AAAAAAAABWg/Yn2CtB66sbY/101_1793.JPG
The baton you will be pleased to know, is topped by that globe-like thing made of sterling silver. The stick is wrapped with sterling silver bands naming the band… Complete waste of money.
Hey, it’s not like they buy a new one for every season; and at least there’s one piece of military gear that probably is a good deal if it costs its weight in silver 
Which is another cool thing about the Old Guard F&D Corps – their DM carries an actual steel-tipped weapon (… lessee… right: an “espontoon” it sez here) rather than a decorative mace like the band’s DM.
Si Amigo: The point was, that in the US Military, apparently only the Drum Majors wear those as part of their dress uniform, as opposed to the whole regiment.
Am I the only one who thought '‘Wow, that hat’s so big, they had to give him a cane to find his way around!’? 