I don't think fiddler will help you with getting their colors as it will list every possible color, as well as the base type in the object list section... I suggest just searching for every type of color for each box type.
I'm not sure how to approach that in EUO anymore but in stealth it's super easy...
FindTypeEx($0000,$FFFF,BackPack,True); (Replace $0000 with the type. $FFFF = anycolor.)