Thank you for sending the photo. It looks like the veins are darker green than the rest of the leaf. The smaller leaves are also pale in color. These symptoms lead me to have two guesses. The first is that the shrub has white fly or mites and you can check for these sucking insect by examining the back of the leaf closely with a magnifying glass. Tiny webs (spider mite) or flying white insects when you spray with water (white fly) are signs of these two common summer insects. They can be controlled with an insecticidal soap or strong jets of water on the shrub every day for a week or so to disturb the colonies. Dry plants are more susceptible to both these insects. My other guess is that lack of nutrients is causing the small leaves and lack of color. Use a complete fertilizer such as Osmocote Plus around the base of the shrub and water in well. Sometimes a shrub in a container that is watered often will suffer from lack of nutrients when all the fertilizer is washed from the soil. A mulch of compost on top of the roots will help to ensure moisture and add nutrients to the soil. Keep growing, Marianne Binetti