What causes your indoor plant to yellow?

Answer 1

They turn white because there is no sunlight, the chloroplast gives the plants their color but without sunlight the chloroplast slowly in a way kinda fade & let other colors such as white show instead of the usually green.

Answer 2

[1] Yellowing may result from lighting, nutrient, pH, predator, space, temperature or watering problems. [2] Check the lighting and temperature needs. [3] The plant may be iron or nitrogen deficient. If the plant doesn't green within a week of applying nitrogen fertilizer, then add chelated iron. [4] Do a soil analysis. The plant's acidic/neutral/alkaline preferences must match the soil's pH. A pH that's off makes nutrients such as calcium, iron, magnesium, manganese, and phosphorus unavailable to plants. [5] House plants may yellow from above and below ground predators. Fungi and nematodes damage and discolor roots. Aphids, mites, and scales attack leaves and stems. Magnifying lenses and microscopes show them, their eggs, their cast-off bodies. Use horticultural oil or insecticidal soap. [6] Roots may not have enough room. Repot in a container that gives 2" more room. [7] Overwatering or poor drainage may be a problem. Except in high heat/light situations, plants generally don't need to be watered more often than every 7-10 days.