Well if being stuck here in the first place is any indication of their sense of humour I can't say I'm entirely surprised.

[Okay, that is a new one on her and she looks very much confused]

Okay, how does that even work? Ignoring the fact that you have the blood of the Messiah or however it is we're supposed to regard the Signless and his non-spectrum descendent, your blood colour is your blood colour. Except, I guess, when it's not...wait but how does that work with other stuff? Isn't that all the same colour as your blood too?