Original: The satellite appears neutral ( grey ) in the visible light ( colour indices B-V = 0.80 , R-V = 0.39 ) Tommy Grav , Matthew J. Holman , and Wesley C. Fraser Photometry of Irregular Satellites of Uranus and Neptune , The Astrophysical Journal , 613 , ( 2004 ) , pp .
Simplified: The moon appears grey in the visible light Tommy Grav , Matthew J. Holman , and Wesley C. Fraser Photometry of Irregular Satellites of Uranus and Neptune , The Astrophysical Journal , 613 , ( 2004 ) , pp .