I got my new K-2006 kit in and started the learning process.

I know that to check combined chlorine, you begin to drop one drop the R-0871 reagent until the mixture turns from pink to colorless. I noticed that if allowed to sit for a short time (3 -10 sec?) the mixture begins to turn pink again.

At what point do you say the mixture is "colorless?" Do you keep adding drops until the mixture stays "colorless" even after sitting for a time or do you stop counting the first time it become colorless?