The most common factors for yellowing money tree leaves are too much sunlight, wide range of temperature fluctuations throughout the day and/or over-watering. It is best to keep the plant away from sunlight and in a neutral location as to temperature. Avoid placing it next to windows and vents. Watering should be done around the soil of the trunk and not directly onto the trunk to prevent rotting. It is best to give small amounts of water and allow the soil to almost dry out before the next watering. If using a water/moisture meter, the reading should be kept between 1-3. Green food can also be used to help the plant reach its maximum green color and strength and is more effective when the leaves are just turning pale.
However, in some cases it is normal for some of the leaves to turn yellow due to natural aging of the plant. Simply cut the unwanted leaves off so that new ones can grow and replace. Do not leave yellowing leaves on until they turn brown since it can spread decay to other parts of the plant.