May regulate MYC transcription factors. Involved in epidermal cell fate specification such as trichome and root hair development, seed mucilage production, and anthocyanin biosynthesis by acting at the dihydroflavonol-4-reductase (DFR) step. Together with GL1 and GL3, promotes trichome formation. Activates the transcription of GL2. Interacts directly with GL3 and BHLH2. Part of a complex made of GL1, GL3 or BHLH2, and TTG1. Interacts with CCT8 (PubMed:21868675). Roots, leaves, stems, meristems, flowers and flower buds.