You have a phosphorous deficiency if you are experiencing white leaves with your plants. You will need to have them fertilized to help out the plants. You can do this soon.
Powdery-coated leaves indicate mildew. Humidity and bad air circulation usually are the causes for this. A low-toxic fungacide, such as Green Cure, is effective. When watering, keep off leaves.
Its looks like having mildew. This happens because of air is humid or low air circulation. Water the plants in the evening to stay wet at night. Use least-toxic fungicides.
Most possible your geranium gets too much light, this plant likes shades. Put it somewhere with less light and in a time being white leaves will fall and plant go back normal.
