Hello, according to the height and weight measurements you shared (1.68 cm, 56 kg), size S will provide the ideal fit for you in our products. (If you prefer a more flowing fit, you can also consider size M.) Regarding color details; the fabric of our products has a melange (self-textured/mottled) structure. Due to this special texture, our Ecru melange tone has a light gray appearance, while our Gray color is in Medium Gray / Smoke gray tones, which is different from the anthracite tone and is specific to the melange structure. Both colors have a different and more profound presence than plain, single-colored products. We wish you pleasant shopping