Natural pigments are increasingly promoted as sustainable alternatives to synthetic colorants; however, their environmental performance remains insufficiently quantified and difficult to compare across biological kingdoms. Existing studies are fragmented, rely on heterogeneous methodological assumptions, and rarely allow direct comparison of production efficiency, processing intensity, or life cycle impacts. This review consolidates current knowledge on pigment production from plants, microalgae, fungi, and bacteria, offering a cross-kingdom evaluation of technological maturity, yields, scalability, downstream processing requirements, and environmental burdens. Plant-derived pigments are technologically mature but limited by land and water use and low extraction selectivity. Microalgal systems demonstrate high productivity but are constrained by energy-intensive harvesting and cell disruption processes. Fungal and bacterial platforms provide high productivity and chemical diversity, yet remain challenged by complex downstream processing, regulatory uncertainty, and low technology readiness for food applications. Comparative insights from available Life Cycle Assessments (LCA) indicate that sustainability outcomes depend more on processing technologies, energy intensity, and production scale than on biological origin. Nevertheless, inconsistent functional units, system boundaries, and reporting practices hinder robust benchmarking across kingdoms. To address these limitations, this review proposes a cross-kingdom conceptual value chain and identifies priorities for harmonizing LCA methodologies and enhancing transparency. Overall, advancing sustainable pigment production will require integrated process optimization, standardized environmental assessment, and clearer regulatory pathways to enable industrial uptake.
Minaya et al. (Fri,) studied this question.