The best products I know in terms of small particle size, PPM and surface are range in color from amber to brownish with a slight green tint and are quite transparent. Ionic silver tends to be clear and may turn yellowish after it sits for awhile, assuming it was made with pure water devoid of any chemicals or contaminants. Never use tap water and also note that using distilled water off the grocer's shelf is not enough to guard against such contamination.
The silver I am most familiar with has four separate filters, each of which cost more to replace than the most expensive complete home silver kits - up to $1500 apiece.
Darker, non-transparent colors can be the result of contaminants or large particle sizes, and one or both is likely the case is you get dark murky product you make at home. It is worth noting that true colloidal silver can change in color to gray after it has been opened and comes in contact with the air, but should not be a cause for worry.
Clear silver which remains that way for an extended time can be an indication of very weak concentrations of silver and not of high product quality.