From Katcher:-
1) 1st MA – deserter in brown coat with red cuffs, so possibly a regimental coat and therefore a uniform.
2) 2nd MA – green COats faced red, but these not issued until Dec '77; prior to that, deserters all wore different clothes.
3) 4th MA – as posted above, blue coats faced white (or possibly light buff) quite early on; this appears to be confirmed by descriptions of 11 deserters in June '77, seven wearing blue with white facings, and four white with blue facings (ie musicians – these included both the drum-major and fife-major who had laced coats; two drummers also had hunting shirts, but no colour listed).
4) 5th MA – only recorded deserter had a blue coat lined red with white facings, narrow-brimmed round hat.
5) 13th MA – deserters give no real clue to uniform.
Two general points:-
a) Most of the Northern Army did not receive any major issues of clothing until after October '77 – ie they fought teh campaign in civvies. What few uniforms were issued early on in the campaign appear to have gone to NCOs (possibly the poorer officers, too). Thus a typical unit fighting Burgoyne's army probably looked like militia with uniformed command figures.
b) Blue, brown (aka "snuff" or "tobacco"), and off-white (aka "stone" or "cloth-coloured"), were far and away the most common colour for jackets, coats and overcoats (surtout) worn by deserters; these colours plus red and green were common in small clothes (ie breeches and waistcoats/vests). In most cases it is a fair bet that the deserter was still wearing what he had joined up in – in fact, non-issue of promised clothing is suspected to be a major cause of desertion (usually combined with lack of pay). Thus we cannot always assume blue or brown as a uniform.