Phase-angle dependence of colour ratios and potential implications for lunar remote sensing Yazhou Yang, Pei Ma, Le Qiao, Hao Zhang, Weidong Jin, Te Jiang, Yang Liu and Yongliao Zou A&A, 644 (2020) A30 Published online: 26 November 2020 DOI: 10.1051/0004-6361/202039385