Hardy often describes Henchard's eyes as being dark and intense, imagery that supports the idea that however "bland" or normal his outward appearance may seem, his interior life is shadowy and profound. When he first meets Elizabeth-Jane in person in Chapter 10, not knowing about their alleged relationship, she observes this darkness without knowing anything else about him:
His dark pupils—which always seemed to have a red spark of light in them, though this could hardly be a physical fact—turned indifferently round under his dark brows until they rested on her figure. “Now then, what is it, my young woman?” he said blandly.
The "darkness" of his pupils and the "red spark" that appears within them lends him a sinister demeanor right from the outset. Even though it can "hardly be a physical fact" that his dark eyes spark red, Elizabeth-Jane is immediately uneasy.
Other aspects of his appearance are also linked to images of darkness and evil, and the "redness" with which Hardy describes the flash in his eye and other aspects of his body also has implications of addiction and anger. The color red is often linked in Victorian literature to intense, uncontrollable masculine emotion. A consistently red face or nose in novels of the time is also an unmistakeable indicator that a character is an alcoholic. In addition, the colors red and black were commonly used in art, poetry, and religious imagery in Hardy's time to represent the Devil's supposed presence in evil deeds done by man. As Henchard does a lot of nasty things and is also the primary antagonist of the novel, this imagery evokes and represents his fundamental badness on many levels.
An unnerving combination of red and black in aspects of Henchard's body regularly appears in moments where Hardy describes him in times of great stress or intensity. His complexion in this same interaction with Elizabeth-Jane is "rouge-et-noir," French for "red and black." When he wrestles with Donald Farfrae, red of face and gasping for breath, Hardy calls him an "infuriated Prince of Darkness." Finally, in the skimmity-ride that truly seals the fate of his reputation with the town, the figure that represents Henchard is easily recognizable to the townsfolk as him because it has "black whiskers and a reddish face." The connotations of the repeated red and black imagery around Henchard are not subtle: he is an antagonist inside and out, and everyone eventually sees it.
Throughout the book, Michael Henchard’s body is associated to varying degrees with images of redness, flushing, and blood, particularly in his face. Hardy does this because the color is traditionally associated with lust and anger, but also for another important reason that would have been more evident to a Victorian audience. At the beginning of Chapter 33, when Henchard is found to be publicly carousing, his face has taken on the tell-tale hue of alcoholism:
The flush upon his face proclaimed at once that the vow of twenty-one years had lapsed, and the era of recklessness begun anew.
A red face in Victorian literature, particularly a red nose, was a warning sign of a habitual drinker. Though Henchard is a teetotaler for most of the book, he is morally “stained” with the aftereffects of his vices, literally making his face take on a reddish hue. When he succumbs again in Chapter 33 to his “era of recklessness” after 21 years of sobriety, the “flush” returns, signaling his downfall.
The “recklessness” referenced here is also associated with Victorian tropes of redness or bloodiness. When characters become “flushed” in Hardy's novels, it is usually “with anger” or “with embarrassment," not necessarily with the overconsumption of alcohol. The way Hardy employs the imagery of redness in The Mayor of Casterbridge evokes all of these sensory implications together to complete the picture of the “lapsed” Henchard as an angry, drunk figure whose "red" physical body betrays his mental state.