I have done this with coleus plants that develop a stem that's a "sport". Sports are common in coleus. Sometimes those colors or traits do seem to stay stable, a least few a few generations. Maybe eventually they'll revert back to look like the original but I have one that seems to be staying stable in the second generation.
If you get whole plants with that foliage, let me be the first on your begging list for a cutting of it.
Karen
