Hess diagram of tiles b278 (left panel; l ≈ 1° and b ≈ −4°, with 0.12 ≲ E(J − K_s)≲0.67) and b320 (right panel; l ≈ 1° and b ≈ −1°, with 0.40 ≲ E(J − K_s)≲5.30). Different polygons are used to roughly highlight some of the sampled evolutionary sequences: the bright disk MS (blue polygon), the bulge RGB (black polygon), the RC (red polygon), and the blue plume of evolved disk sequence (green polygon).