Oh yeah, I'm going here. In ST6, it's pink. Everywhere else, it's regular red blood. Of course, it was pink is ST6 so that we'd be able to see that "this is not Klingon blood!" Such a plot device was not required anywhere else. So, given the importance given to Klingon blood colour, I personally tend to think that it's always "meant" to be that colour. Thoughts? Anyone agree or disagree?