Left panel: classification results across the H–R diagram colored by subtype. Spectral subtype changes as color and temperature change—warmer, bluer stars (K5.0) are of earlier subtypes, and later-type stars are cooler and redder in color (M8.5). The color bar on the right side of the panel shows the color-map for the subtypes—later-type stars are depicted in redder colors. Left panel: classification results across the H–R diagram colored by the morphology class parameter. Metal-rich stars are depicted in red while the most extreme metal-poor subdwarfs are depicted in blue/purple. Metallicity increases up through the main sequence from the metal-poor subdwarfs (MC = 12.5) to the metal-rich dwarfs (MC = 0.5).