These are the colors (Testors) which I've found most closely match the pictures (boxes, Osprey books, etc.). For one shade colors, here are the Testors numbers; black (1149 or 1749), white (1168 or 1768), gold (1144 or 1744), silver (1146), steel (1180 or 1780), brass (1182 or 1782), flesh (flat-various available shades or mixtures). Testors is sold in Europe under the name "Model Master".
NOTE: colors based on the Osprey books- Men At Arms series #69,Elite series #7B,Warrior series #27, and the box art.
ALL COLOR NUMBERS ARE TESTORS UNLESS OTHERWISE STATED.
NOTE: Except for the popular reds, tunic and crest colors are pretty much optional.
White is the most common cuirass color but others also seem to have existed.

CAVALRY
BODY PART(S)--COLOR
tunic--insignia red 1705
cuirass,helmet,sword handle,crest holder--brass
belt--leather 1736
waist plates--white
spear--wood 1735
hands,face,legs--flesh
hair--brown,ital.dark 2111
sword,spear tip,tunic clasp--steel
high crest--insignia red 1705 and white
low crest--insignia red 1705
horse--white or black
saddle,straps--leather 1736
saddle trim--gold
strap buttons,bit--steel
base--green 2029





CHARIOT
BODY PART(S)--COLOR
officer cuirass,helmet,greaves,sword handle--brass
officer tunic--insignia red 1705 or bright blue 2032
officer waist plates--insignia red 1705 and white
officer belt--leather 1736
officer hands,face,legs--flesh
officer helmet crest--insignia red 1705 or insignia red 1705 and white
officer sword--steel
driver tunic--insignia red 1705 or inap. violet 2013
driver belt,whip--leather 1736
driver hands,face,legs--flesh
driver hair,beard--brown,ital.dark 2111
chariot frame,wheels,horse rack--wood 1735
chariot--insignia red 1705
chariot rim and handholds--brass
chariot design--gold
chariot wheel rim and axle--steel
horses--black or white
horse rack trim--brass
horse rack plumes,body straps--insignia red 1705
horse head straps--leather 1736
horse strap buttons--steel
base--green 2029