Hmmm...what I understood is that meters were calibrated to a reflection standard, 18% or 12% whatever the manufacturer wishes. Certainly the color will have an effect on the response of the meter but I think people are confusing meter response to film response. B&W film, with exception of TMX or ACROS have a lower response to tungsten light than to daylight. I beleive in Toms case he was seeing the film response and the meter was accurate measuring the amount of light. This is why is recommended to test film response to tungsten light.