The environmental and health-related impacts of synthetic dyes have led to growing interest in natural dyes as sustainable and eco-friendly alternatives. However, natural dyes have been used to dye textiles with limited color shade and poor fastness properties, and little research has been conducted in this field. Additionally, natural dyes also have the potential to provide added functionalities to textiles, such as antibacterial and anti-UV properties. A systematic literature review of 38 studies was conducted to analyze the use of six natural dyes derived from eucalyptus (Eucalyptus globulus Labill.), weld (Reseda luteola L.), madder (Rubia tinctorum L.), annatto (Bixa Orellana L.), true indigo (Indigofera tinctoria L.) and woad (Isatis tinctoria L.). These dyes were selected after a preliminary analysis of studies on plant-based natural dyes with primary colors, considering their chromatic and potential medicinal properties. This study explores the influence of different dyeing parameters and auxiliary products in these properties. The research discussed how the chromatic and medicinal properties of natural dyes can be affected by various factors and provides a summary table with the chromatic palette possibilities according to the different materials and processes relationships. Exploring the combination of natural dyes with environmentally friendly auxiliary products can be a promising development area for creating a wide range of color shades. Further research is also needed to optimize the dyeing processes with natural dyes, towards more sustainable textile dyeing possibilities.

Ultraviolet radiation (UVR) represents significant risks to both textile durability and human health. Natural dyes are gaining attention as eco-friendly alternatives to synthetic UV-blocking agents, offering aesthetic and functional benefits. This study explores the UV-protective properties of 100% cotton knit fabrics dyed with natural dyes—indigo, weld, and madder—using different mordanting processes, including materials with mordant abilities such as alum, pomegranate peel, and tannin extracted from quebracho. Twenty samples were evaluated, including undyed, individually treated, and combined dye-mordant formulations. UV protection was assessed through spectral transmittance and Ultraviolet Protection Factor (UPF) measurements before and after washing. The results showed that natural dyes significantly improved the UV resistance of cotton fabrics, particularly when combined with products like pomegranate and the tannin–alum mixture. Notably, some samples demonstrated improved UPF and became darker after washing, such as mordant combinations like tannin with alum. These findings suggest that natural dye, when combined with appropriate mordants, offers a sustainable and effective approach to producing UV-protective textiles. This is particularly valuable in children’s clothing, where chemical safety and sun protection are crucial. Future research should investigate the influence of pH on dye stability and UV-blocking performance to optimise formulations for industrial use and long-term functionality.

Functional textiles and clothing designed for children should provide a safe and supportive environment, encompassing comfort, safety, health, wellbeing, and cognitive development, as well as fostering interaction and exploration. This study explores the multifaceted nature of functional textiles and clothing for children. It emphasises the importance of comprehensive knowledge about the user and an interdisciplinary approach in the design process. The integration of expertise from diverse fields contributes to a holistic understanding of the challenges and opportunities inherent in creating clothing that satisfies aesthetic demands and promotes the wellbeing of children. Through a study of existing research in functional textiles and a market analysis of children’s clothing, this research underscores the importance of practical application of studied materials and technologies in children’s fashion, creating innovative and purposeful solutions. This collaborative effort involves working with multidisciplinary teams and applying designers’ updated knowledge of functional materials throughout all stages of the design process. The study emphasises the designer’s responsibility in articulating the essential knowledge needed to integrate functionality from the beginning of the design process, ensuring that practical considerations are integral to the core attributes of the clothing. The study also proposes a framework that represents the design process for functional children’s clothing.

Children’s skin is highly sensitive and prone to irritation, allergies, and infections, requiring special consideration in textile selection. Although clothing serves as a protective barrier, it can also pose a risk when dyed with toxic chemical colourants. This study explores the potential of multifunctional natural dyes as safer alternatives for children’s clothing, particularly for those with dermatological conditions. Cotton knitted fabrics were dyed through exhaustion with extracts of madder root (Rubia tinctorum L.), pomegranate peel (Ppe, Punica granatum L.), oxidised logwood (Logox, Haematoxylum campechianum L.), and tannin from quebracho (Schinopsis lorentzii Griseb.), both individually and in various combinations with or without potassium aluminium sulphate dodecahydrate (alum). The combination of madder and Ppe demonstrated the most promising multifunctional performance, being classified as a weak disinfectant against S. aureus (3.7 log reduction) and showing the highest antioxidant activity (92.6 ± 2.56% 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical reduction), while maintaining excellent results after washing. Moreover, these natural formulations expanded the achievable colour palette from each dye while maintaining moderate wash fastness. The results highlight the relevance of these findings to textile and fashion designers, offering sustainable tools for creating health-conscious, visually appealing garments. This research reinforces the potential of natural dyes and biomordants in developing functional textiles that support children’s wellbeing and environmental responsibility.