Hi Adelmanto,
To those variegated plants, there is a middle to be found in between full shade and full sun .
In full shade, the leaves are more likely to turn solid green.
In full sun, the leaves are more likely to turn to almost all white - the problem being that the white zones don't contribute to the photosynthesis for the plant.
So you need to find an half shaded location, with some sun .
Every now and then, whatever you do, some leaves will turn all green .
Keep experimenting and keep us posted, for the ones like me that don't have that strain - for now at least :) .