#4 and #8 IH plows were basically same paint schemes. Hitch and coulter arms are black. Axles, hubs, lifting springs, back of moldboards and lifting mechanism parts are IH blue. Frame and rest of parts are IH red. Wheels are IH white.
IH #2150 red is used nowadays.
IH blue not available, but NAPA has #53-3736A for correct match and other brands can match it also. Ford blue is not the same.
IH 935 White is a cream color, close to same as on hoods of 560, 460, etc.
This site might have what you need and I know that Carter and Grueneveld (sp?) also has paints for plows...see their website; C & G IH dealer.
LA in WI