Fulvic acid is the lowest molecular weight portion of humic substances. By definition it will be golden in colour where humic acid will be brown to black. the fulvic is absorbed almost instantly (facilitating the delivery of the 74+ nutrients it contains), while the humic passes through the digestive track (where it aids in digestion) By the way, Humic AND fulvic have a very earthy taste (like soil), while fulvic alone has a very strong taste (like lemon).