Fig. 2

B. mori cocoon shell colour phenomics. (a) Correlation in contemporary cocoon shells between Green channel values and Brightness values on the RGB and HSB scales⁶⁴. For colour coding of the samples in this and all subsequent panels of Fig. 2, see⁶⁵. (b) Correlation in the contemporary cocoon shells between Blue channel values and Saturation values. (c) Correlation in the contemporary cocoon shells between Hue and Saturation values on the HSB scale. The Hue values are expressed as point in the colour wheel. (d) Correlation in the old cocoon shells between Green channel values and Brightness values⁶⁴ (e) Correlation in the old cocoon shells between Blue channel values and Saturation values. (f) Correlation in the old cocoon shells between Hue and Saturation values om the HSB scales. The Hue values are expressed as point in the colour wheel. (g) Correlation in the old cocoon shells between Green channel values and Brightness values after adjusting the original colour of the samples using the equations shown in Methods section. (h) Correlation in the old cocoon shells between Blue channel values and Saturation values after adjusting the original colour of the samples using the equations shown in Methods section. (i) Correlation in the old cocoon shells between Hue and Saturation values om the HSB scales after adjusting the original colour of the samples using the equations shown in Methods section. (j) Reconstruction of the original colour of the old cocoon shell samples in Photoshop v. 20.0.3 (upper row) and fluorescent colour images of the cocoon shells upon exposure to 365 nm UV light (lower row). Numbers indicate each sample’s ID¹⁹. * Sample No. 142 had the lowest fluorescence intensity values of all the samples shown in Fig. 1d appearing extremely dark, with a Hue value of 220° and the lowest Blue channel value of all the samples in (j) The colour images of Fig. 1d were used to reconstruct their original colour in Photoshop v. 20.0.3. The original and adjusted RGB and HSB values are shown in⁶⁵. (k) Clustering of all the cocoon shell samples to 8 distinct clusters based on their colour appearance upon UV light exposure as shown in (j). The samples were classified according to the presence of green pigments on the cocoon shell, their original colour (White/Coloured) and the presence of fluorescence as recorded in Fig. 1d. Numbers indicate each sample’s ID¹⁹. Numbers in red indicate the old cocoon shell samples and numbers in black the contemporary cocoon shell samples.