How pink is pink??? (acid testing with a kit)

Okay, I apologize if this has been asked before but I couldn't find it and hopefully this isn't a totally dense question but I obsess:

I used an acid testing kit for the first time on a pail of Pinot Grigio juice today. I understood that, as I added the testing chemical, I was supposed to watch the test sample for when it turned pink and stayed pink, and I was shooting for a final acidity of .70. The starting value I got was really low, but I added some acid blend to the must and then some more until the test sample I drew turned and stayed pink at .70. Well, then I added a little more of the testing chemical to the sample just to see what happened and it turned really dark pink and stayed that way.

So... would the reading be when the sample first turns and stays pink, or when it's dark pink? I'm hoping just pink is all right, because that would be .70. Otherwise, I may have added too much acid blend...

when it first makes a change you have the info you need....all subsequent changes are of no matter and will give you a false reading and false information to then act upon...it is the first significant change ie from white to pink that stays pink...not that color change that occurs when you first drop the solution in and then swirl or stir and also not the subsequent changes that occur from pink to dark pink or red for example

Seeing this change can be difficult even for the most experienced. A different set of eyes can easily see the change at different times. If you have a pH meter, or access to one, you can confirm when the change happens. It will be at a pH of 8.2 .

additionallyif you do have color change-itis...you can hold the sample up against a white piece of paper and take digital pics of teh initial sample to compare with....all you have to do is look through the view finder or view screen and see what you may otherwise forget

Thanks, guys! It's actually very similar to testing the water in our swimming pool, but I wanted to make sure it was the first stable change (i.e. turns pink and stays pink) that I was looking for.

WHEW! :-D This wine is off to a wonderful start...