Do CPLs cause a color caste?

[Kayaker72]

I had always assumed this was a given, as I read it on the internet (Link under "which one to choose"), so it must be true.

Below is a picture that I've always attributed to the color cast from a CPL (taken with B+W 72 mm MRC CPL):


Beach IMG_4075 by kayaker72, on Flickr

I processed the above shot using DPP back when I had just started learning post-processing (still so much to learn). So, I took another stab at it with lightroom 4 this morning:


small-4075 by kayaker72, on Flickr

That is getting closer to how the scene looked (it is a beach we go to every year), but still something is missing from the grasses. But it also took adjusting the color temp, saturation, vibrance, tone and yellow & green slider bars for both Hue & Saturation. And it still isn't quite right.

So, I am curious, anyone else feel that their CPL gives a slight color cast? I understand that in theory, the CPL is just blocking wavelengths, but I had thought practice was a bit different.