If you can, take pictures and post them or send them to me. I haven't seen a yellow CC result with DPD-FAS testing.

And yes, I meant, let the pool water + OTO sample stand for 10 minutes before trying to read it.

You can probably resolve some of the DPD-FAS testing confusion by buying a gallon of distilled water from Walmart and mixing 1/2 cup of pool water with 1/2 cup of distilled water, and then testing THAT, for FC, CC, and pH. Multiply the FC & CC results x2; take the pH result as is.