lol, prompts come from the strangest places 😆
Yeah, the 30eme changed a lot. 1805 they were in the "standard" habit longue and bicorne, with regimental distinctions mainly limited to the regiment number on buttons, cartridge box covers etc.
In 1806, regulations called for the shako to replace the bicorne, on a 3-year issuing cycle. At the same time, voltigeurs (light companies, one per battalion) were created. The shako had a diamond-shaped plate. The regulations said voltigeurs got a chamois-coloured collar and yellow pompom on the shako as their company distinctions. But the regulations were massively ignored - they were an elite company and adopted as many of the distinctions grenadiers (the other elite company) had, but in variations of yellow/red/green instead of the pure red of grenadiers. For the 30eme, it included epaulettes in yellow and a yellow over red plume.
After the 1807 campaign, a whole bunch of regiments with a "3" in the number, including the 30eme, adopted Polish-style sunburst shako plates. The 30eme were heavily involved in the campaign, and it's possible (but uncertain) that the voltigeur companies may have switched all yellow epaulettes for yellow ones with red crescents.
In the 1809 campaign, the 30eme were again in the thick of things, and by the end their uniforms would have been shredded. So they re-equipped. This time, they adopted the new design of shako plate (a Phrygian shield with lions heads - the one I use on my shako). The voltigeurs went for green epaulettes with a yellow crescent and a yellow plume with green tip.
Then in 1812, on the eve of the Russian campaign they re-equipped again, going into the new Bardin regulation uniform, which was a bit simplified but recognised the reality of what soldiers in the field were actually doing. Voltigeurs got all yellow distinctions but were supposed to hand their sabres back in.
And believe it or not, that little essay is just a brief overview of a few key points ! 😀