How to read coolant test strips

[JimT]

Also, per the instructions, you need to check the results within "75 seconds". Perhaps the colors continued to shift after that time making it harder to identify on the chart?

it also says, in my own words, to use Price Is Right rules and pick the closest matching pad without going over.

... I tell you, if more things were explained based on Price Is Right rules, then the world would be an easier place!