In the journals of Lewis and Clark, "deep sea green" emerges as a striking and recurrent color motif, predominantly used to describe the eyes of subjects with an almost otherworldly quality. The color is often linked to the pupil, depicted as uniform and piercing—sometimes occupying a substantial portion of the eye, and at other times contrasted with irises of bright yellowish silver or pale golden hues, creating an arresting interplay of light and shade [1, 2, 3, 4]. Additionally, the hue occasionally appears alongside or in juxtaposition with black, enhancing its mysterious and multifaceted character, as seen in descriptions that note a circular deep sea green pupil edged with a ring of yellowish brown or described as moderately large yet penetrating [5, 6, 7, 8, 9, 10]. This deliberate use of deep sea green not only helps to define physical features but also imbues the narrative with a symbolic depth, evoking the enigmatic and unfathomable mysteries of the natural world.