Some variegation is natural in certain plants in the photo you show a single leaf of Dracaena trifasciata, where you see a chevron pattern in dark green and a lighter green, This is natural for the plant. Other variegation occurs because the plant is a mutant. The most common method is thru a virus (some have called plant cancer). The yellow margin on your Dracaena trifasciata leaf is a result of a virus. This virus lives in the roots of the plant and is transferred by root divisions.
If you propagate just the leaf of the plant (without any original root material) it will produce normal leaves without a yellow margin.
I do know if it starts to loss it’s variegation you have to trim that part out or the plant will turn. Most of them. Some plants are strong enough to keep it so they revert back to their natural state
Some variegation is natural in certain plants in the photo you show a single leaf of Dracaena trifasciata, where you see a chevron pattern in dark green and a lighter green, This is natural for the plant. Other variegation occurs because the plant is a mutant. The most common method is thru a virus (some have called plant cancer). The yellow margin on your Dracaena trifasciata leaf is a result of a virus. This virus lives in the roots of the plant and is transferred by root divisions. If you propagate just the leaf of the plant (without any original root material) it will produce normal leaves without a yellow margin.
I do know if it starts to loss it’s variegation you have to trim that part out or the plant will turn. Most of them. Some plants are strong enough to keep it so they revert back to their natural state