There are several reasons the leaves on a jasmine will turn color.
(Chlorosis ) One is the soil, when there is a lack of iron, the leaves will turn yellow or light green, sometimes off white and the veins will remain dark and the leaf stays strong.
If you take a plant and move it from one location to another and the amount of light it gets will change the color of the leaves. Shade loving plants in too much sun suddenly...they can actually get sunburned.
Low light will make the leaves turn grey and dry up.
Overwatering is more dangerous than underwatering. Leaves become papery , thin, fade and very often turn yellow starting from lower branches and the tips may turn brown and dry. Unfortunately the symptoms are nearly the same for both.
Low humidity can cause leaves to look dry, deformed and drop off.
Over fertilizing can cause leaves to wilt, turn grayish, sometimes dry on the tips and turn dark.
There are more, but these are the most common.
Just thought I would give you an idea of how many different things can affect the color of your leaves. Nothing is easy.
