was, of course very, fashionable.

Beau Brummell helped make the plain but well, tailored coat an item of desire among fashionable gentlemen of our era .He is thoguht to ahe adopted teh blue caoss and buff waistcaot as being of the political perusasion of Fox and Sheriden.

This is a watercolour of Brummell in his blue coat circa 1805( painted by Richard Dighton)

And here is a picture of Sheriden , in his unofficial uniform of blue coat and buff waistcoat as adopted by members of the Whig political party.

However, Brummell's influence made the wearing of blue coats popular even among non-supporters of that party. Here is a description of Brummell's style from Blackwood’s Edinburgh Magazine, 1844.:

His person was well formed, and his dress was a matter of extreme study.

But it is rather libelous on the memory of this man of taste to suppose, that he at all resembled in this important matter the strutting display which we have seen in later times, and which irresistibly strikes the beholder with surprise, that any man capable of seeing himself in the glass could exhibit so strong a temptation to laughter; while to the more knowing in the affairs of costume, it betrays instantly the secret that the exhibitor is simply a walking placard for a tailor struggling for employment and supplying the performer on the occasion with a wardrobe for the purpose. Brummell’s dress was finished with perfect skill, but without the slightest attempt at exaggeration.

Plain Hessian boots and pantaloons, or top boots and buckskins, which were then more the fashion than they are now, a blue coat, and a buff-coloured waistcoat–for he somewhat learned to Foxite politics for form’s sake, however he despised all politics as unworthy of a man born to give the tone to fashion–was his morning dress.

In the evening, he appeared in a blue coat and white waistcoat, black pantaloons closely fitting, and buttoning tight to the ankle, striped silk stockings, and opera hat.

We may observe how much Brummell went before his age; for while he thus originated a dress which no modern refinement has yet exceeded, and which contained all that is de bon ton in moderate equipment, he was living in the midst of a generation almost studiously barbarian–the Foxite imitators of the French republicans–where every man’s principle was measured by the closeness of his approach to savagery; and nothing but the war interposed to prevent the sans-culottism alike of the body and the mind.

Aileen Riberio in her book The Art of Dress has this to say about Brummell's influence:

The Prince ( of Wales-JW) must occasionally have cast an envious eye over the slim figure of his sartorial mentor, George 'Beau' Brummell, who had resigned his commission in the army to devote himself to a 'life of pleasure'.

This mainly consisted of a club-man's masculine way of life, revolving around St James's, to which he brought wit and superb good taste, particularly in dress.

He it was who turned the art of masculine attire into the supreme expression of being a gentleman; he helped to create a look exquisite tailoring and the careful selection of acessories for its effect.

Harriette Wilson's Memoirs record how Brummell's word on dress was Iaw; men "made it a rule to copy the cut of [his] coat, hat, or the tie of his neckcloth' - even the Prince of Wales was reputed to watch him dressing. Typical obiter dicta included: 'No perfumes, Brummell used to say, but very fine linen, and plenty of it and country washing', and, 'If John Bull turns round to look at you, you are not well dressed, but either too stiff, too tight, or too fashionable' .

Brummell's conception of what a gentleman should wear was based on neatness, cleanliness, harmony and lack of affectation. His views on dress followed those of Lord Chesterfield in the mid-eighteenth century that an Englishman should choose the happy medium between an excessive reliance on the latest fashions and being quite indifferent to them .

In Brummell's Male and Female Costume, a survey of dress, part-historical, part-contemporary, which he composseed during his exile, he noted that 'there is quite as much vanity and coxcombry in slovenliness as ther is in the most extravagant opposite', and he attacked " the minor poet who goes into company with a dirty neckcloth and straggling locks', just as mjuch as the 'dandy who scorns to have an id-e-a beyond the set of his clothes' .
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Brummel eshewed the extravagnce of dandy-ism and the Macaroin's of the 18th century and preferred plain ,well cut , clean clothes:

His morning dress was similar to that of every other gentleman-Hessians and pantaloons, or top-boots and buskin, with a blue coat,and a light or buff coloured waistcoat; of course, fitting to admiration on the best figure in Engalnd. His dress of an evening was a blue coat and white waistcoat, black pantaloons which buttoned tight to the ankle,striped silk stockings and opera hat; in fact he was always carefully dressed,but never the slave of fashon.

Captain W Jesse The life of George Brummell 2 vols London 1844.