A Google Books search finds four instances of "rose-colored glasses" from the years before 1850. From Mary Boddington, Slight Reminiscences of the Rhine, Switzerland, and a Corner of Italy (1834):
O the joy of blossoming life! What a delicious thing it is to be young, and to see everything through rose-coloured glasses ; but with a wish to be pleased, and a certain sunniness of mind, more in our power than we imagine, we may look through them a long time. When the sun shines, and the earth holds a bright holiday, I still feel as if life and hope were all before me, and yet the story i told out and out as far as belongs to dreams and fancies ; and yet I dream on, and love flowers, and air, and sunshine, as if I was but just beginning life.
From Mary Davenant, "The Ideal and the Real," in Godey's Lady's Book (October 1843):
"A man in love is easily deceived. I have seen more of life than you have, my dear, simply because I look at people with my own eyes, instead of through rose-coloured glasses as you do, and I never see a woman who appears so very soft and gentle that she cannot raise her voice much above a whisper, and whose every word and look betrays a studied forethought of the effect they are to produce, that I do not mistrust her sadly. Half of them re shrews, and the other half obstinate intriguers‚I am much mistaken if Mrs. St. Clair is not a little of both."
From "Elliotson's Principles and Practice of Medicine," The Boston Medical and Surgical Journal (December 13, 1843):
The gentleman last named in the above somewhat extended overture to the work before us, is an old and valued personal friend of the writer of this brief notice. We have studied with him, ausculted with him, travelled with him, and in all these relations he has been among our most esteemed associates. If there were some good reason for valuing his talents and acquirements in the days of our personal intercourse, there is the same reason for hoping that he would not have published a book without merit, and that his friend need not be obliged to look at his labors through the rose-colored glasses of personal kindness to see them under a favorable aspect.
From W.A., Fewell: A Series of Essays of Opinion for Churchmen (1846):
But, however, looking at the position of the clergyman under this system, it is manifestly a temptation of that position to strive after popularity ; to be easy and compliant ; to inquire but little; and to permit the decencies, and suitabilities, and respectabilities of society to take the place of discipline—in short to see every thing rose-color; and if rose-color be not there, to put upon his nose rose-colored glasses.
These four instances show the range of attitudes that can be encompassed by the phrase. In Boddington's travel memoir, rose-coloured glasses are a kind of natural sunniness of outlook that goes some way toward transforming the world into the optimistic image of it that the young person has. In Davenant's story, the glasses are a source of deception for the wearer, who leaves common sense behind when he puts them on. In the review of "Elliotson's Principles," the glasses are a form of intentional self-delusion, committed out of sentiment or personal friendship, that prevents an honest critical appraisal. And in W.A.'s essay for churchmen, wearing rose-colored glasses entails denying or ignoring unpleasant truths in order to be liked.
Yet another attitude appears in "Quackery," in The St. James's Medley (May 1865):
A lover of fiction, and of vivid fancy, he [the auctioneer] flourishes his hammer, and by its transmuting touch converts a tumble-down cottage in a swamp into an elegant and commodious villa on the bank of a beautiful river. He considers it his duty to make the best of everything, viewing it through rose-coloured glasses; and if he does represent this or that article to be in better condition, or more valuable than it is, he does but exercise a legitimate trickery, which he considers to be the high art of his profession.
Here the rose-coloured glasses are, in effect, shared by the huckster with his audience of potential rubes: He wears them to describe the imaginary beauties of the things he is trying to sell, and the audience wears them to imagine that what he says is true.