Dr. Ronald Gibbs booklet states that high-quality Colloidal Silver is colorless, but the highest particle surface area colloid in the tabulations is dark in color, why this discrepancy?
The material in Ron Gibbs book is slightly dated. Ron died in May 2000 and the book material was frozen about a year before. For example, the samples that Ron tested, some of which were made for him in the Colloidal Science Lab. Inc.(CSL) were believed by Ron to be at least 50% colloidal when in fact they were mostly ionic (typically 90%). The methods developed at CSL to determine ionic vs. particle concentration were just being developed at the time Ron wrote the book and so he was not fully informed about the ion/particle ratio of the test samples and consequently made some erroneous assumptions. Ron assumed the sample was at least 50% particles when they were only 10%.
Since true colloids of high particle concentration had not yet been developed when Ron wrote the booklet, all products of that time which displayed color were the result of large silver particles present in ionic solutions that were produced using electrolysis methods. Those products contained about 10% of the silver content in the form of particles. For a solution to display color while containing such a relatively small amount of particles requires that the particles be quite large (typically 100 – 500 nm).
True silver colloids that have a high percentage of the silver content in the form of nanometer-sized particles will absorb visible light causing the apparent color to appear dark-amber or brown. It is the very high concentration of particles, not large particle size or contamination, that gives these products such color.