The antonyms for the phrase "retro versions" can vary depending on the context it is used. However, some possible antonyms include "modern versions", "contemporary versions", "forward-looking versions", "futuristic versions", "innovative versions", "avant-garde versions", and "advanced versions". While retro versions signify a throwback or nostalgic appeal, these antonyms convey a sense of progress, novelty, and experimentation. Modern versions often feature sleek and minimalistic designs while contemporary versions embrace the latest trends and materials. Forward-looking and futuristic versions may present bold and radical advances in technology and aesthetics. Innovative and avant-garde versions can challenge conventions and push boundaries, while advanced versions boast the highest levels of performance and functionality.