What color light shall I test under?

[moseley75]

Florescent light has a blue cast and incandescent light is redish.
The light in my kitchen is florescent. While testing PH, using a Red Sea test kit, I had the test on the range b/c it provides a pure white background. My shadow was falling across the test so switched the range light, incandescent, on and the color changed from greyish (8.0 pH) to purplish (8.2 pH). While I don't believe this is a terrible problem I find it interesting.
Is there a light source that won't effect the color of the test?

 

[AdamNC]

This is the bulb I use. I've read around that 6500k is the most natural color to use

 

[AdamNC]

I also tried to post a topic about this but got little response.

https://www.reef2reef.com/threads/lighting-for-reef-testing.306892/

 

[saltyfilmfolks]

A tip I like is to not try to match the color. Try to detriment the contrast between the colors. (Think black and white), if you squint your eye a bit you can see the subtle differences in them.

I use a lot of different colors of light in my work. So choosing one is impossible.

 

[JimWelsh]

This can be a huge problem, depending on the specific color change of the test, the color temperature of various lights in the room, and even the degree of colorblindness of the tester! For certain tests, like a calcium test, where the color change is from purplish to a clear blue with no hint of red, an overly red light source can be a real problem. I find diffuse natural sunlight to be the best light source for testing. While 6500K lamps claim to be close to natural sunlight, I still find them to be way too red.