Aiming at the ambiguity in explaining the color mechanism of fiber aggregates by the existing color-spinning color matching models, the color change mechanism of dope dyed viscose fiber aggregates during spinning was explored. In the experiment, 36 groups of sliver andyarn samples with different color mixing ratios were spun, and the Euclidean distance and spectral angular distance were used to quantify the spectral amplitude difference and shape difference between the fiber aggregates of different states in each group. The chromatic aberration, which was calculated based on the CMC(2∶1) formula was evaluated as a control, and the quantified spectral difference and chromatic aberration were compared horizontally based on the discrepancy criterion based on the category separable ratio (CSR) formula. Among them, between the raw sliver and the drawn sliver, the mean values of CSRED and CSREcmc of the samples were 2.87 and 2.17, the dED of the sample is similar to the performance of ΔEcmc, and the spectral radiation difference is more stable than the color difference. Between the sliver and the yarn, the dED and Ecmc have the same trend of greater changes, and all the samples CSRED and CSREcmc are greater than 1; in the above process, the shape difference of the sample spectrum keeps a small scale, before and after drawing and spinning, there are 20 and 22 samples corresponding to CSRSAD>1, and their mean values are 1.69 and 1.60, respectively, which did not change significantly with processing. It can be concluded that during the spinning process, due to the remodeling of fiber arrangement and aggregation state, the amount of reflected light(brightness) tends to decrease, and the spinning stage is the main stage of change, while the light quality(hue) not significantly changed during this process. Further, according to the light reflection theory of the fiber, that is, the amount of the reflected light of the fiber is mainly affected by the externally reflected light, and the chromaticity is mainly affected by the internally reflected light. It can be concluded that the spinning process mainly affects the external reflected light of the fiber. However, it has little explanatory power for internally reflected light. On the other hand, it also verified the ability of the SAD-ED formula, which integrates spectral amplitude and shape features, to characterize the color difference of colored yarns. CSRSAD-ED can distinguish 31 groups of sliver and drawn sliver samples and can distinguish all drawn sliver and yarn samples, this formula shows more sensitive and stable than the CMC(2∶1) formula, which is the color difference. This scheme also provides a new idea for the color evaluation of colored yarns.