Sonnet 127, which begins the sequence dealing with the poet's relationship to his mistress, the Dark Lady, defends the poet's unfashionable taste in brunettes. In Elizabethan days, so the poet tells us, black was not considered beautiful: "In the old age black was not counted fair, / Or, if it were, it bore not beauty's name." However, what is considered beautiful — at least to the poet — has changed; "now is black beauty's successive heir." This change in what is considered beautiful is the poet's main concern here in Sonnet 127 and in succeeding sonnets.
What most upsets the poet is not that one definition of beauty supersedes another but that women use cosmetics to enhance their natural appearance. This unnatural practice creates artificiality, "Fairing the foul with art's false borrowed face." Even worse, cosmetics devalue the ideal, or standard, of what beauty is, for they allow women to change their appearances on a whim according to what is currently deemed beautiful. Constancy in what is beautiful is sacrificed for fickle, mercurial notions of how a woman should look: "Sweet beauty hath no name, no holy bower, / But is profaned, if not lives in disgrace."
The degree of emphasis on the Dark Lady's color varies in the sonnets, so sometimes she seems black-haired and other times merely brunette. The poet's appreciation of the Dark Lady's appearance is complex: He is glad that she does not use cosmetics to lighten her appearance, which would be "a bastard shame," but she is not physically attractive to the poet, for all her erotic appeal. However, her black eyes become her so well "That every tongue says beauty should look so." Black, then, becomes another means for the poet to discredit the use of cosmetics; his mistress' good looks are not "slandered" by unnatural measures.