10G single fiber optical module wavelength and pull ring color are 1270nm (black), 1330nm (blue), 1490nm (purple), 1550nm (yellow). This article provides a professional guide on transceiver pull tab color codes by wavelength—spanning SFP, SFP+, CWDM, and BiDi modules—and introduces how LINK-PP standardizes color matching across its optical product lines. The topic of specifications and physical traits is one aspect of this question; another often-overlooked detail is the color of the pull tab. This modest. The color of the small pull tab on an optical module, while seemingly insignificant, hides a wealth of crucial information. Let's uncover its mysteries with Xiaoyi.