Red：1-3 DRY (Red zone: Dry to slighty humid, for plants such as Cactaceae, thickleaved plant, Sansevieria, etc.)
Green: 4-7 NOR (Green zone: Slightly humid to humid, right for most plants, such as Begonia, Cyclamen, Euphorbia, Ficus, Fuchsia, Philodendron, Geranium, Saintpaulia, Azalea, Adiantum etc.)
Blue: 8-10 WET (Blue zone: Very humid, do not water, don't drown your plants.)
