Test Kits - Who makes the best?

[Black Phantom]

I'm sure we are all in the same boat. Look at your test under a MH bulb and it looks fine. Move over to a household fixture with a 3500K bulb and things are out of whack. Go outside or move to a window with good sun and you get another color reading.
I'm so confused
And unfortunately the manufacturer never includes instructions as to what your light source should be.