A few observations and questions so anyone can help:

Did the leaves used to be dark green and are now turning yellow-ish or is it vice-versa? Seem like new leaves are the only ones doing that. New foliage can start much lighter colors and then turn dark green. If that happened, it is ok. If the reverse happened, it may be useful to monitor it.

I could not enlarge the pics enough to check for chlorosis (see if the leaves are turning light green or yellow, except for the top leaf veins which remain dark green). However, chlorosis is not usually limited to new foliage strictly. Can you please take a look at the leaves and comment about that?

Have you recently checked the soil pH? You have a cemented area and the house wall, both quite close, so I wanted to know if the two things might be related and leeching lime.

For whatever that is worth, I am also noticing that the plant on the right also has light green leaves and a tad darker on the bottom but it could just be shade.

When the plant gets too much sun, the leaves in direct contact with the sun turn yellow but that is not true here. Only the new foliage is affected.

Does it have mulch? The soil appears dry. Have you fertilized or amended the soil recently?

Sandy soil can lack some nutrients (nitrogen for example) and cause the leaves to turn some colors. From the picture, the soil does not look sandy. But where are you located (city, state)?

How many years has Preziosa been in this location?

New foliage may be more sensitive to sunlight if winter protected. Was Preziosa winter protected? Or to very low night time temperatures.