I am going to chime in here and offer my support to Jock with regards the Kenneth MacLeay watercolours, My opinion of most of the paintings is one of pure make believe, pure folly, granted a few of the subjects could have, and probably did wear the attire they are depicted as wearing on a daily basis especially if they where under the employment of Queen Victoria, John Brown is a prime and obvious example, (why does John Brown always remind me of Billy Connolly) but take a look at the Campbells painting, it features Colin Campbell, now this subject was a tenant farmer, meaning he paid rent for his patch of land, he didn't own it, he was also a fisherman, probably both at the same time, such was the harsh way of life at that time, he lived at Kenmore on the shores of Loch Fyne (Scotlands longest sea loch) just to the south of Inveraray, now this is a place I know well, I pass it regularly on my way to and from my place of work, and I can tell you it's an idylic location.... NOW, but back in the late 1800's, well I don't think Colin Campbell would have felt the same way, he would have considered it home yes, a place to bring up a family, but with no modern ammenities, only a small patch barely a few acres to grow crops and a steep mountainous backdrop behind the farmstead only fit for a few sheep to graze, his life would have been hard, subsistence living almost, no government handouts, no charity, he had to live on his wits and make the most of everything, so could he have afforded such a splendid outfit, could he hell as like, few today in this buy on credit cards age can afford or justify such finery, I strongly suspect it was provided on loan by the Duke of Argyll himself who choose who he wanted to sit for these portraits himself, and the same with all the other clansmen depicted.
Do I think these paintings are indicative of the dress of the period, Obviously the wealthy could have afforded such attire, but I think the falsehood lies within the dipiction of ordinary folk wearing clothing above and beyond what they could have afforded or suited the nature of the work.
No it's pure Victorian Fantasy, eye candy for the Queen.