Still working through the list, but here's my first set of recommendations in (r,g,b) format. From these I'd recommend using the ore colours for aluminum, antimony and copper. I recommend salt colours for chromium and cobalt.

Aluminum

Metal: Base: (128,128,128) Specular: (224,224,224)

Ore: Base: (165,42,42) Specular: (255,128,0)

Salt: Base: (224,224,224) Specular: (255,255,255)

Antimony

Metal: Base: (96,96,96) Specular: (224,224,224)

Ore: Base: (96,96,96) Specular: (160,160, 160)

Salt: Base: (224,224,224) Specular: (255,255,255)

Chromium

Metal: Base: (128,128,128) Specular: (224,224,224)

Ore: Base: (96,96,96) Specular: (192,192,192)

Salt: Base: (102,0,255) Specular: (204,153,255)

Cobalt

Metal: Base: (126,131,126) Specular: (224,230,224)

Ore: Base: (178,73,46) Specular: (199,139,117)

Salt: Base: (51,153,255) Specular: (153,204,255)

Copper

Metal: Base: (255,128,0) Specular: (255,204,153)

Ore: Base: (0,102,51) Specular: (0,153,76)

Salt: Base: (0,204,102) Specular: (0,255,128)

Here's the completed list, with my personal recommendations marked by asterisks. Sorry for taking so long.

It may also be possible to differentiate ores by giving them unique shapes (like the long rods of stibnite, magnetite's octahedrons, etc.) Hope this helps!

Gold

*Metal: Base: (168,102,11) Specular: (249,249,221)

Ore: Base: (111,101,74) Specular: (245,244,231)

Iron

Metal: Base: (151,150,146) Specular: (205,205,204)

*Ore: Base: (117,117,117) Specular: (235,235,235)

Salt: Base: (68,18,7) Specular: (126,24,9)

Lead:

Metal: Base: (137,137,139) Specular: (199,199,199)

*Ore: Base: (95,95,93) Specular: (248,241,235)

Salt: Base: (168,31,0) Specular: (206,59,0)

Magnesium

Metal: Base: (131,129,116) Specular: (232,234,231)

*Ore: Base: (189,163,116) Specular: (239,233,210)

Salt: Base: (123,118,122) Specular: (216,216,216)

Mercury

Metal: Base: (97,97,85) Specular: (253,248,247)

*Ore: Base: (141,59,61) Specular: (205,202,216)

Salt: Base: (146,146,142) Specular: (177,176,174)

Molybdenum

Metal: Base: (97,95,94) Specular: (238,237,237,)

*Ore: Base: (215,105,47) Specular: (231,192,178)

Salt: Base: (218,117,4) Specular: (255,236,167)

Nickel

Metal: Base: (179,176,167) Specular: (254,255,250)

Ore: Base: (94,84,49) Specular: (252,247,217)

*Salt: Base: (81,213,156) Specular: (202,243,237)

Platinum

Metal: Base: (163,164,158) Specular: (227,232,228)

*Ore: Base: (156,160,161) Specular: (232,232,232)

Salt: Base: (205,81,38) Specular: (242,147,56)

Plutonium

*Metal: Base: (161,144,144) Specular: (227,207,206)

Salt: Base: (78,80,30) Specular: (125,130,64)

Promethium

Metal: Base: (81,80,78) Specular: (254,253,249)

*Ore: Base: (94,105,111) Specular: (206,210,213)

Salt: Base: (230,232,179) Specular: (232,233,194)

Rodnium (numbers based on rhodium)

Metal: Base: (144,130,119) Specular: (248,246,244)

Ore: Same as platinum/nickel

*Salt: Base: (51,37,40) Specular: (96,80,83)

Silver

Metal: Base: (143,139,136) Specular: (238,246,247)

*Ore: Base: (78,94,94) Specular: (249,249,250)

Salt: Base: (222,222,232) Specular: (219,219,230)

Tin

Metal: Base: (73,75,58) Specular: (253,253,238)

*Ore: Base: (72,81,90) Specular: (238,241,248)

Salt: Base: (250,254,253) Specular: (250,254,253)

Titanium

Metal: Base: (177,169,158) Specular: (255,254,253)

*Ore: Base: (50,49,48) Specular: (194,103,34)

Salt: Base: (137,122,116) Specular: (246,249,245)

Tungsten

Metal: Base: (169,167,154) Specular: (215,212,203)

*Ore: Base: (80,87,97) Specular: (236,235,235)

Salt: Base: (213,210,138) Specular: (234,238,178)

Zinc

Metal: Base: (160,160,162) Specular: (247,248,243)

*Ore: Base: (92,92,94) Specular: (250,250,248)

Salt: Base: (188,184,173) Specular: (251,252,247)