Coloring the substrates with plasmonic nanomaterials, also known as nanocoloration, has introduced a nascent way for coloration without using any dye that has extensive detrimental environmental effects. In this research, a one-step process for coloration of the wool via plasmonic anisotropic selenium nanocrystals is introduced. Synthesized selenium nanocrystals are one-dimensional and have trigonal geometry which is known to have exquisite physical properties. Also, they indicate rigorous antibacterial activity against Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans). Selenium nanocrystals have homogenously distributed on the wool fibers with an average size of 68 nm; as well, some selenium nanoneedles with the size of less than 10 nm were synthesized nevertheless such a small size of selenium nanoneedles never has been reported. The fabric color had changed to the coral color. The plasmonic nano-Se@wool nanocomposite also established better mechanical properties, hydrophilicity, chemical stability, and anti-felting properties. In this way, a facile promising method was presented for sustainable development to introduce an alternative way for fabric coloration without any dye with the hope of being useful for scalable production.