Well? Did oil and water separate from your cloudy radiator water? I don't think the water pump spins fast enough to have emulsified oil & water in your system to that milky color though.
I've worked on enough boilers (hydronic & steam) to recognize dissolved air in water from heat & pressure will make it look milky. The slight orange hue is probably from rusting metal shavings left over from manufacturing or exposed steel surfaces within the cooling system.
I'm dying to find out what it really is.