Christmas cactus is a tropical cactus that grows best in bright, indirect light. It can tolerate some partial shade but won’t grow well in very dark rooms.
The best location for your Christmas cactus is a room that faces east or west. A bathroom or a kitchen with a large window are both excellent choices, and they will also provide your cactus with a humid environment.
Changes in daylight trigger the blooming time for the Christmas cactus. It needs short days, up to 10 hours, and long nights of at least 14 hours.
If your Christmas cactus turns pale green, it could be getting too much direct sun. This often happens, followed by a slight tinge of red color. Think of it as sunburn. Try moving it to a location with more indirect sun.