Colored fibers can be blended in a certain proportion to achieve a specific color. It is a very hard task for the colorist to find a good recipe to meet the final product without the aid of computer. In this article, a color separation method for the colored fiber blends is discussed to substitute for some manual work. The fuzzy C-means cluster is a way to group the color in the colored fiber blends image. The distance index, which is a key factor during the fuzzy C-means cluster process, is calculated in the RGB color space and the HSV color space with some transformation. The final experiment result proved that the colors of each pixel in the blends' image can be replaced by corresponding cluster center associating colors in the HSV color space, and the main texture as well as the main color information about the fibers in the image ispreserved. (c) 2011 Wiley Periodicals, Inc. Col Res Appl, 37, 212-218, 2012; Published online 13 July 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/col.20662