Q.Yellowing leaves on gardenia plant
Most of leaves on my indoor gardenia plant are turning yellowish…hardly any dark green. But plant is blooming and buds still to open. What does it need?

I'm sorry your Gardenia leaves are turning yellow! Have you misted the plant lately at all? Misting is not recommended. Neither is overwatering, which is one of the main causes of leaf-yellowing. This plant requires really bright light so if you've had excessively dreary weather lately, that could be the cause.
This article may help you:
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/gardenia-plant.htm