“Wild” silks, produced by various silkworm species and often valuable in textile collections, are generally more difficult to dye than “domestic” mulberry silk from Bombyx mori, for reasons that are still misunderstood. The impact of the main components of wild silks (fibroin and sericin proteins, calcium oxalate) on dyeing remain poorly known. Yet, their characterization is critical as their nature and quantity could explain the variability in appearance of the silks after dyeing. As a hypothesis, calcium oxalate crystals could make degumming of silk less effective, since they could bind physicochemically to sericin proteins which are normally removed during this process. In the presence of this amorphous protein glue surrounding the two strands of semi-crystalline structural fibroin proteins and sticking them together, dyeing of silk could then be less efficient, since the material would be less permeable. To test this hypothesis, it was deemed relevant to study the impact of silk cocoon degumming on its composition, and ultimately, on the effectiveness of the subsequent dyeing. A wide range of silk samples, including cocoons and threads collected from Asia and Africa, were finely characterized by FTIR and Raman to analyze their chemical compositions, enabling at the same time to obtain precious data for the identification of silk fabrics within heritage textile collections. FTIR allowed a semi-quantitative study of calcium oxalate, the crystals of which were found to be naturally very abundant in some wild cocoons and absent in others. The technique was also used to assess the proportion of amorphous regions compared to crystalline regions of silk proteins, enabling an approximation of the proportion of sericin in the samples. In addition, a degumming protocol was established to study the impact of this step on the compositions of the various silks and on the dyeing applied subsequently. All silk samples, degummed or not, were dyed with turmeric or indigo dyes, and FTIR and Raman were used to study the physicochemical interactions. The proportion of turmeric dyes absorbed within the samples was quantified using UV-Vis spectroscopy on the clear dyeing solutions after their application. The data were correlated with the degumming loss (i.e., loss in mass) values, as well as the calcium oxalate and sericin contents estimated by FTIR, which allowed proposing explanations for the differences in appearance after dyeing. Thus, it has been shown that the dye is better absorbed by the silks when the loss in mass during degumming is high, and that the abundance of calcium oxalate crystals may hamper the dye uptake. The results are exploited as part of the ongoing TUSSA project, funded by DIM PAMIR and in collaboration with ANR WILSILKS, which aims at studying furthermore the impact of mordants and characterizing the degradation phenomena of colored wild silk fibers over time.