The antonyms for the rusty-brown color are fresh, vibrant, bright, colorful, and sleek. These colors are associated with newness, energy, and excitement. Fresh shades of green, pink, and blue are perfect antonyms for rusty-brown. Vibrant colors like red, orange, and yellow denote enthusiasm and passion, while bright hues of purple and turquoise make things look lively and cheerful. Colorful is another fitting antonym for rusty-brown as it references a variety of shades and tones. Lastly, the sleek is the opposite of rusty-brown because it refers to surfaces that are smooth, polished, and shiny. These antonyms convey a sense of modernity and sophistication, which contrast with the old and worn-out look of rusty-brown.