History of the Jats, Pathans and Sikhs, ca. 1768
Francis Xavier Wendel
He did more: having returned from his reveries, whether true or feigned, having showed his disciples the arms that Baba-Nanec had presented them with, he himself limited their mode of dressing and colour that he said he had been inspired to make known to them, that is, to let their hair and beards grow, to dress in no colour but blue, made of indigo.

Du Perron’s Indian Researches, ca. 1788
Poor or rich they are always dressed in blue.”…”Their weapons are the lance, the saber and the shield.

A Treatise on the History, Religion and Culture of the Sikhs, ca. 1787
Antoine Louis Henri Polier
Their Dress is extremely scanty, a pair of blue Drawers, a kind of chequered Plaid worn partly round the middle and partly over the shoulder with a mean blue Turban forms all their Equipage.

Treatise on the Sikhs, ca. 1788
Lt. Col. James Browne
“their dress is dark blue, as ordered by Gooroo Gobind, and gives them, when collected in large bodies together, a very dismal appearance.”

The History of the Reign of Shah-Aulum, the Present Emperor of Hindostaun, ca. 1798
William Francklin
The dress of the males consists of a coarse cloth of blue cotton, thrown loosely over the shoulders, and coming down between the legs, is confined round the waist by a belt of cotton. An ample turban of blue cloth covers the head, and over this is frequently wore a sash of silk and cotton mixed, resembling both in colour and pattern a Scotch Tartan.

Memoir of the War in India, ca. 1806
William Thorn
They differ from the rest of the Hindoos in the article of dress no otherwise than by giving the preference to blue cotton cloths, and silks of the same colour.

A Translation of the Seir Mutaqharin, ca. 1789
Ghulam Hussain Khan, translated by M. Raymond, 1789
They form a particular society as well as a sect, which distinguishes itself by wearing almost always blue cloaths (v), and going armed at all times.

(v) It is true that they wear only a short blue jacket, and blue longdraws: but they use likewise the yellow and the white in their turbans, as well as the blue, although by the by the latter is the general colour.

A Translation of the Seir Mutaqharin (The Review of Modern Times) ca. 1763
Mir Ghulam Hussain Khan, translated by M. Raymond, ca. 1789
The Sycks are Deists in the strictest sense of the word, and of course, perfectly tolerant and harmless; although as soldiers, they are, like the Marhattas, merciless plunderers, and incessant skirmishers. The ceremony of the reception of a Proselyte consists in no more than these two articles: to put on a short dress, of a blue colour, from head to foot; and to let one’s hair grow from head to foot, without ever cutting or clipping or shaving it. One day I got within one of their temples, invited thereto by the tingling of the cymbals: on appearing within the door, an old venerable man bid me leave my slippers, as none could enter, but bare-footed. This admonition I obeyed, and went into a hall covered with carpets, at the northern part of which, there were several cushions covered with a yellow veil, under which, I was told lay Nanec-Shah’s book, who is their legislator. At the southern end of the hall, there were fifteen or twenty men all in blue, and with long beards, sitting, some armed and some not. At the eastern side, but very near to it, two old men with a small drum and a pair of cymbals, were singing some maxims of morality out of that Book, and this they did with a deal of enthusiasm and contortion. On getting within the hall, I saluted the company, which returned the salute, and returned it again when I came out.

Sketches Chiefly Relating to the History, Religion, Learning, and Manners of the Hindoos, ca. 1790, Quintin Craufurd
Blue, which is generally considered as an inauspicious colour by the Hindoos, distinguishes the dress of the Seiks; as if Nanuck meant to show by this, the weakness and absurdity of superstitious prejudices. Their dress commonly consists in blue trowsers of cotton cloth; a sort of plaid generally checkered with blue, which is thrown over the right shoulder, and a blue turban.

A Journey from Bengal to England, ca. 1783
George Forster, 1783
In this matter I speak from personal knowledge, having in the course of my journey seen two of their parties, each of which amounted to about two hundred horsemen. They were clothed in white vests, (lxvii) and their arms were preserved in good order
lxvii : A long calico gown, having a close body and sleeves with a white skirt.

Containing Information Respecting the Character of the Inhabitants on the Banks of the Indus, ca. 1794, John Griffith
They sometimes wear yellow, but the prevailing Colour of their Clothes is deep blue; They make their Turbans capaciously large, over which they frequently wear a piece of pliable Iron Chain or Net work.