Those are nectar dots found outside of pitchers. Sometimes can also see it on leaves and stem depending on the species and hybrids.
Oh ya... about the color change besides amount of light, it is also due to maturity factor. I noticed younger pitcher will usually have less intense coloration, as the nep slowly growing up, you'll start to see the pitcher color up and show more characteristic... My clone is flowering now...
but it's a male...
