Some sections taken directly from multiple different core books on the Blush of Life, every one I can find. It isn't in 1e or 2e at all, or if it is it's very well hidden. First shows up in Revised, isn't called Blush of Life until Requiem and V20. None of them explicitly mention that the fluids produced look like blood, simply that a blood point is used. Since the power is specifically for blending in, I would think it is safe to assume that the aforementioned fluids do not look like blood, nor would they have any of the properties of normal vitae. Requiem is where it first mentions being able to fool a doctor. I think people may be getting confused with the different claim that vampires cry tears of blood.

Top left is Revised, top center is V20, bottom left is Requiem 2e, bottom center is V20DA, and far right is V5.