Question about ppm

I have bought a bottle of Colloidal Silver and the water was brown. This was a 10ppm - 100 ml

I bought a new bottle 25ppm - 300 ml this time the water is totally clear.

I don't understand why. I wonder if i have been fooled. Is it possible to have 25ppm and a totally clear water?

Is there any way to check if there are really Colloidal Silver in the water and is it possible to check the density of Colloidal Silver .

Many thanks.