I'm one of those individuals who has difficulty with some of the color comparison tests. With the ph test, I can't tell one color from the other with direct (or front) lighting. However, if I hold the test up a light source with a consistent background, then I'm better able to make the comparisons. Specifically, I've started holding the test up to my skylight with a blue sky in the background.
Does this technique impair the precision or accuracy of the test in any way?
Thank you in advance for the input!