Temperature Dependent Coloration

Temperature-dependent coloration refers to phenotypic color expression in cannabis plants that shifts based on environmental temperature conditions, particularly during flowering. Cooler temperatures (typically 50–65°F / 10–18°C) commonly trigger anthocyanin and other pigment production, resulting in purple, blue, or red hues in leaves, bracts, and flowers. Warmer conditions generally suppress these pigments, yielding greens and yellows instead. This trait is genetically heritable but environmentally plastic—the same genotype can display different colors under different thermal regimes. Breeders working in this category track both the genetic predisposition for color change and the temperature windows required to express it reliably.

Breeders select for temperature-responsive lines to develop cultivars with predictable color expression for both commercial appeal and genetic documentation. Understanding the threshold temperatures and duration needed to trigger coloration helps breeders stabilize and reliably reproduce phenotypes across grow environments.