heyas; i think the easy answers are: the object colour is the base colour. the ambient colour is the shadow colour. (ie: whatever colour you want to appear when there is no light on the object.) the reflective colour is, i believe, the base colour for the refletion map. (it works like the object colour under a skin map, as you probably have noticed if you ever had your reflection colour set to black and a reflection map turned on.) the highlight colour, now, is tricky. there's two parts to it. the first and most obvious is the colour, it will impart a colour to the higlights of your object. the not-so-obvious is the brightness. the brighter the colour, the stronger and more plasticky the highlight is. this is why most people say to set the highlight colour to black. this causes the highlights not to appear as black spots, but to be subdued, so the skin doesn't have that bright glare on it. you may think that the highlight colour should be a lighter shade of the base colour, but this isn't quite the case. to avoid the plasticky look, you should pick a dark colour. you can use the greyscale stuff for neutral highlights, or pick a dark colour to have coloured highlights. there, thouroughly confused now? :)