Final answer:
In traditional film photography, a yellow sweater would appear as various shades of blue on the negative due to the complementary color relationship between yellow and blue in the subtractive color model.
Step-by-step explanation:
In traditional film photography, the colors present in a photograph are inverted in the negative. Therefore, a yellow sweater in a photograph would appear as the complementary color on the negative. The complementary color to yellow is blue, meaning the sweater would show as various shades of blue on the negative. This inversion is part of the subtractive color model, which is based on the absorption of light. In this model, yellow absorbs the blue wavelength of light, so when light passes through a yellow area on a photographic negative, it is the blue light that is not absorbed and is instead transmitted, producing a blue appearance in the negative.