Blue Skinned Space Babe: I wasn’t actually going to bother with this one, but having been reading this:
…recently, and noting the registry of blue people, well.
There are some.
Eldrae blood is blue, a lovely shade of deep indigo, which has a lot to do with the particular transport mechanisms they’re using in place of hemoglobin. That, though, doesn’t actually affect their basic skin color all that much, since ‘twould seem that eldrae skin cells aren’t quite as translucent as human ones, which is why the baseline as seen in the eseldrae race is white. By which I do not mean “kinda pink”, like so-called “white” humans; I mean white, as in new milk, cream, and not-quite-but-almost albino. Darker (natural; not any of the fifty-seven artificial clade skin tones) eldraeic skin tones, on the other hand, are generally on the pink spectrum – varying all the way down to “rosy copper” in the lumeneldrae – but that’s got nothing to do with blood, and everything to do with pheomelanin and various structural variants on same.
The exception to this is the kireldrae, the smallest of the eldraeic races, one of whose racial characteristics is a certain translucency of skin, and who therefore often are a lovely shade of pale blue. Emphasis on pale: go with the syreen or Outsider’s loroi here for your envisioning, rather than the asari or the jotuns.
So, yeah, we have a few. Probably less than 1% of the population.
(As a side note: of course, any eldrae of any of their races who’s currently blushing and/or flushed is rocking the blueness, ’cause that is down to blood coloration.)