Color composite mosaics of Mercury map-projected (4 km px⁻¹) at the average subspacecraft point (21°N, 184°E) of the Mariner 10 outgoing first-encounter imaging sequence. (A) Mariner 10 three-color composite (R = OR, G = BL, B = UV) differentiates all of the major spectral units observed in the (B) MDIS three-color mosaic (R = 1000 nm, G = 750 nm, B = 430 nm, retrieved from the Astrology Science Center; S. E. Hawkins et al. 2007, 2009; B. W. Denevi et al. 2018). (C) Mariner 10-MDIS hybrid composite (R = MDIS 560 nm, G =  MDIS 430/750 nm, B =  Mariner 10 UV/BL), which emulates the spectral resolution of the (D) MASCS/VIRS interpolated color composite (R =  575 nm, G = 415/750 nm, B = 310/390 nm; N. R. Izenberg et al. 2014) with less noise and interpolation.