Tillandsias are epiphytes and need no soil because water and nutrients are absorbed through the leaves. The roots are mainly used as anchors. It is quite common for some species to take on a different leaf color (usually changing from green to reddish tones), called "blushing", when about to flower.
Most Tillandsias are adaptive and hardy enough to be grown indoors with adequate lighting and care, with most types not requiring any soil or such planting medium. Many enthusiasts may attach these plants to other objects.