Mine is never colored. And I have found that 6 to 10 PPM is sufficient.
The way I use CS is to put it where colds and the flu enters the body.
Places where you might put your hands around the head. Ears, Nose, Eyes, and mouth.
Yes, I put a drop in each Eye.
As a preventative,or if you feel some thing coming on, or going on in the throat area. Using a dropper bottle to put drops in the Ears, Nose. Then gargle with a couple of Oz in the throat.
I havent had a flu shot since the mid 80's, or had the flu, or colds. My first CS generator was Bob Becks that was also a zapper. Can't remember how long ago that was. Use the Silver puppy now.
Other considerations are changing your pillow if you feel something coming on because you will have transferred the bug as you sleep.
If you handle money wash often and spray with CS.
Eat in resaurants often. people.
Handle your food in preparation.
CS is best if you dose repeatedly, not just once.