More specifically, I'm reading a book about the Napoleonic Wars, and the descriptions of the uniforms, particularly the British and the French, are very puzzling to me. Like, the idea of the British wearing ornate bright red uniforms during ranged combat seems very counter-intuitive. Same with the French and wearing blue while they invade Egypt and Syria.
Mainly I was curious as to what drove this more colorful uniform design, and when this shifted to a more camouflage oriented uniform similar to what we see today? Like, was there an underlying function of the more brightly colored uniforms that I'm missing?
Thanks!
There are a few things you have to realise when you think of warfare in older times. I will list them before going further.
Communications within a unit are by shouted order, drums, whistles or trumpets. Orders to the unit are done by flags, runners or messengers or other visual signals.
Cavalry presents a clear and real danger on the battlefield. Any unit unable to keep together is liable to be ridden down and sabared mercilessly by cavalry.
Weapons and training of the era is imperfect and most soldiers will die of disease rather than to enemy action.
The nature of black powder weapons would often quickly shroud the battlefield in smoke, making communication even more difficult.
Most armies used mercenaries or other form of vounteer service to staff their armies in this era.
Open top weapons (such as flintlocks) are highly vurnurable to moisture.
Psychology on the battlefield is very important, as many (if not most) soldiers are killed as they break and run.
Taking these things into consideration, a bright coloured uniform makes a lot of sense. It lets you separate your own men from the enemy easily. The unit is easy to spot on the battlefield for messengers or the general wishing to control it - a unit that cannot keep together and cannot be seen or controlled by the general is worse than useless - it is counter-productive, as it will still draw rations and supplies, but not add to the combat power of the army.
Camouflage is not an issue to the same extent, as a unit kept together in a tight formation to be able to ward of any enemy cavalry and to be able to deliver massed volleys of musket fire. People would not lie down for protection, as it would cause dew (at least in the morning) to foil the gunpowder and it is much harder to reload a muzzle-loaded musket lying down than it is standing up.
A brightly coloured uniform, especially an elaborate one also tells that the unit is well-trained and supplied (there's no sense in spending money on fancy uniforms for bad units), and you will see many notes of well-dressed units running, specifically because it is a noteworthy thing when they do. A smart, fancy uniform also helps when you are recruiting for the unit and instills pride and hopefully a moral superiority in your own men compared to that of the enemy.
That said, light infantry and skirmishers as well as sharpshooters are noted for using dispersed fighting and adapted shooting lying down and camouflage (or at least not brightly coloured uniforms) earlier than regular infantry. Swedish and Finnish Jägare in the Finnish war of 1808-09 were issued grey or green uniforms and rifled muskets. Likewise the British 95th Rifles were issued with Green uniforms.
The British themselves stopped using brightly coloured scarlet uniforms dusing the Boer wars, noting that the grey and tan coloured (often civilian) clothing of their enemies allowed them much better ability to hide on the Veldt of southern Africa. That enclosed cartridge rifles much less vurnurable against moisture had been introduced also helped.
In general the colors came to enhance pride and brotherhood on each side. They also symbolized individual courage, because the soldier wearing such uniform stood out and could be targeted by the enemy. The shift occurred during the mid/late 19th century, first in the Crimean war. It was noticeable in the American civil war and later WW1 where all sides wore neutral colored uniforms to blend in. The reason for change was technological. Progress in the development of firearms and weapons in general. The way they fought and battlefield tactics changed drastically.
Another interesting detail is haircut. In 19th century most soldiers still had long hair. In WW1 with the terrible conditions in trenches, epidemics and lice short haircuts became the standard.
Battlefields were fought with muskets. Blackpowder makes alot of smoke. It's important to be able to see what color uniform you are shooting at.