Answer: To address your second concern first, broadleaf evergreen shrubs routinely lose their older leaves to make room for new growth. If the leaves in question were closer to the main stem than the tip of the shoot, it's the older growth and the plant is probably getting ready to shed some of the older leaves. If the discolored leaves were on the tips of the shoots, the plant may have received too much direct sunshine.
Brunsfelsia floribunda (Yesterday-Today-and Tomorrow), has blossoms that change from purple to lavender to white. 'Magnifica' will perform in a similar manner; there are fewer flowers but the flowers are larger. 'Magnifica' is less cold-hardy than 'floribunda', but that shouldn't be an issue in your southern California gardening region.
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