I sampled one single Paris fashion magazine, and the issues per year. It's target market isn't middle class, but those with money. Napoleon became emperor in 1804. Plates were acquired and reused by other fashion magazines. So it was influential and aspirational.
I was motivated to do this by hearing a strong assertion from someone - that the only historically accurate colour for upper class women to wear at this time period is white.
Every museum collection has been curated. That is, items have been selected or discarded for a theme, or an individuals taste, or a new direction/perspective of a new curator or what is approved by the museum board. No museum has the space or financial resources to collect everything. Museums deaccession, to make room or money for other purchases. So each museum collection has been formed through bias. What forms that bias or consecutive possibly different bias may never be known. They are not an accurate representation of the complete past, but a blurred window on snippets of it.
I pinned all the An 9 Costume Parisien fashion plates and there are 85 different plates in the French Republic year or An 10, which was around 23-ish September 1800 to 23-ish Sept 1801. I mention -ish because the revolutionary calendar year started on the [northern hemisphere] autumn equinox.
15 out of 85 aren't relevant as they're for menswear or bonnets, leaving 70 relevant fashion plates.
Of the dresses:
- 36 of 70 are white gowns ... 6 of which are worn with a coloured spencer or bodice but they remain white dresses.
- 8 of 70 are white with a coloured over shortgown/tunic
- 21 out of 70 are a colour
- 5 coloured gowns have a white over shortgown/tunic
So in that 22 Sept 1800-01 year, 51% of aspirational gowns were plain white, 49% weren't.
An 10 Costume Parisien issues contained 83 different fashion plates (so 23-ish September 1801 to 23-ish September 1802)
11 out of 83 aren't relevant as they're for menswear or bonnets, leaving 72 relevant fashion plates.
Of the dresses:
40 white dresses - of which 4 have colour motif print
9 white dresses with coloured over dress
22 colour dresses - of which 2 are print and 1 is broad stripe
1 colour dresses with white overdress
So in that 22 Sept 1801-02 year, 56% of aspirational gowns were plain white, 44% weren't.
An 11 Costume Parisien issues contained 68 different fashion plates (so 23-ish September 1802 to 23-ish September 1803)
20 out of 68 aren't relevant as they're for menswear or bonnets, leaving 48 relevant fashion plates.
Of the dresses:
24 white dresses - of which 1 has colour motif print
11 white dresses with coloured over dress
11 colour dresses - of which 1 is a narrow stripe
2 colour dresses with white overdress
One of the plates has an infant wearing a coloured dress which I've not included above as it could be either male or female.
So in that 22 Sept 1802-03 year, 50% were plain white, 50% weren't.
Anyhow, this is only a 3 year sample of inspirational/aspirational fashion images from one influential magazine.
Here are some links to not-all-white fabric Costume de Bal aka ball gowns.
https://www.pinterest.com/pin/115756652899519440/ same plate different bodice, not sure which is the original
and all white fabric Costume de Bal
https://www.pinterest.com/pin/115756652899519526/ with green trim
https://www.pinterest.com/pin/115756652899517214/ with green & purple trim
https://www.pinterest.com/pin/115756652899520320/ with buff trim
https://www.pinterest.com/pin/115756652899520282/ with printed short overskirt
https://www.pinterest.com/pin/115756652899523277/ with printed overskirt
https://www.pinterest.com/pin/115756652899520965/ with green trim
So even the 6 white fabric ball gowns have coloured trim, and there's 4 colour or colour with white underskirt Ball Gowns. None are white on white with white trim!