Institute for Color Science and Technology with scientific cooperation of Iran Color Society Journal of Color Science and Technology 1735-8779 20 1 2026 05 22 Synergistic Effects of Natural Colorants Derived from Oak bark, Spent Coffee Grounds, Cinnamon, and Clove on the Colorimetric Properties and Fastness Performance of Dyed Wool Fabrics Synergistic Effects of Natural Colorants Derived from Oak bark, Spent Coffee Grounds, Cinnamon, and Clove on the Colorimetric Properties and Fastness Performance of Dyed Wool Fabrics 1 15 82190 10.30509/jcst.2026.167781.1283 FA Majid Tehrani Department of Art, Shahrekord University, P.O. Box: 5681188617, Shahrekord, Iran Mousa Sadeghi-Kiakhani Department of Organic Colorants, Institute for Color, Science and Technology, P.O. Box: 16765-654, Tehran, Iran Fatemeh Zarei Department of Art, Shahrekord University, P.O. Box: 5681188617, Shahrekord, Iran Journal Article 2026 03 03 <em>Environmental pressures and emerging requirements for cleaner production across the textile industry value chain have highlighted natural dye–based approaches and low-impact mordanting systems as practical alternatives for textile coloration. In this study, the synergistic effects of four natural dye sources including oak bark, spent coffee grounds, cinnamon, and clove, on the colorimetric properties and fastness performance of wool fabric were investigated. The performance of the metallic mordant alum was compared with that of a bio-mordant derived from pine-cone, and the influence of mordanting technique was evaluated under pre-mordanting, simultaneous, and post-mordanting conditions. The results indicated that oak bark and clove, owing to their high polyphenolic content, produced greater (7.38 and 8.24) color depth. In binary and multicomponent dye combinations, reduced reflectance in the 400–500 nm region and enhanced absorption were observed. When alum was used as the mordant, post-mordanting generally yielded the highest color strength, whereas pre-mordanting provided more favorable results in the case of the pine-cone bio-mordant. Washing fastness ratings were predominantly in the range of 4–5, and light fastness values were approximately 5–6, indicating acceptable color stability in the dyed samples. Overall, the findings demonstrate that the targeted design of natural dye combinations in conjunction with low-impact mordants enables the achievement of warm hues with satisfactory fastness properties and can be proposed as a practical strategy for sustainable dyeing of wool fibers.</em> <em>Environmental pressures and emerging requirements for cleaner production across the textile industry value chain have highlighted natural dye–based approaches and low-impact mordanting systems as practical alternatives for textile coloration. In this study, the synergistic effects of four natural dye sources including oak bark, spent coffee grounds, cinnamon, and clove, on the colorimetric properties and fastness performance of wool fabric were investigated. The performance of the metallic mordant alum was compared with that of a bio-mordant derived from pine-cone, and the influence of mordanting technique was evaluated under pre-mordanting, simultaneous, and post-mordanting conditions. The results indicated that oak bark and clove, owing to their high polyphenolic content, produced greater (7.38 and 8.24) color depth. In binary and multicomponent dye combinations, reduced reflectance in the 400–500 nm region and enhanced absorption were observed. When alum was used as the mordant, post-mordanting generally yielded the highest color strength, whereas pre-mordanting provided more favorable results in the case of the pine-cone bio-mordant. Washing fastness ratings were predominantly in the range of 4–5, and light fastness values were approximately 5–6, indicating acceptable color stability in the dyed samples. Overall, the findings demonstrate that the targeted design of natural dye combinations in conjunction with low-impact mordants enables the achievement of warm hues with satisfactory fastness properties and can be proposed as a practical strategy for sustainable dyeing of wool fibers.</em> https://jcst.icrc.ac.ir/article_82190_2c083f689c0062c9872f2f52953baa26.pdf