One of the most apparent markers of identity and station in society has been clothing and accouterments. Based on what fashions you wore, you could be identified as rich or poor; married or unmarried; young or old... During the French Revolution, the material of society dramatically changed, causing incredible, visible changes in the fashions from that era onward. For men, these new fashions would define the standard for men's apparel for the next centuries - for women, the change was only a temporary reprieve from the extreme voluminous skirts and under garments.
Prior to the French Revolution:
The center of fashion was firmly set in Paris prior to 1789; it took it's cues from the Court of Versailles where the mode of dress favored extravagant yardages of fabric and sumptuous trims. Patterns were allowing for extra volume in the skirt and sleeves, making the garments ungainly and obviously best suited to the more privileged classes who had more leisurely lifestyles.
(A fashion plate showing the extreme fullness of a dress skirt, accomplished with the help of stays, panniers and culs worn underneath.)
Men's apparel was highly ornate as well, often with gold embroidery and luxuriant trimmings and lace cuffs.
During the French Revolution, clothing became highly symbolic of one's political persuasions and social class... during The Terror, it was not only fashionable, but it was indeed safer to embrace a more naturalistic style that had up until then been associated with the lower, working classes. The dress of the Old Regime had favored silks, velvets, laces and ribbons - the colors for both men and women's dress were bright, highly eye-catching shades. Inspiration for fashion now shifted to English styles: he candy-colored fabrics fell out of style and were replaced with darker, more sensible fabrics, like cotton and embroidery was kept to a minimum.
Les Incroyables and
les merveilleuses were enamored of the clean tailoring and playful and dashing associated with their new-found
l’anglomanie. 
Here a side-by-side comparison shows the difference in decoration of both sets of clothes - in addition to the waistlines becoming drastically high in comparison to those worn before, all of the excessive lace and frippery were removed.
For men, breeches with white stockings slowly transitioned to trousers and pantaloons (pantaloons were essentially breeches that reached to just below the knee for wearing with tall boots). Trousers, which had been a working man's staple previously, were seen worn by the upper classes by 1807 - which only makes sense as society found equilibrium, there was a general shift towards wearing the styles of the common people.
A blue coat was a particularly patriotic choice in France... color became very important in conveying one's solidarity with the new republic.
