The antonyms for the word "rust-colored" are numerous and varied, given the wide range of colors seen in nature. Some potential antonyms include shades like white, beige, cream, ivory, and off-white, which are all light and pale colors that are a far cry from the reddish-brown hue of rust. On the other end of the spectrum are darker shades like black, charcoal, navy, and midnight blue, which offer a sharp contrast to rust-colored objects. Brighter colors like aquamarine, turquoise, and teal also serve as excellent antonyms, evoking a sense of coolness and freshness that is completely opposite to the warmth and earthiness of rust.