In the context of viewing blood in a vacuum, what is necessary for the true spectral properties of the fluid to dominate what an observer sees?

Answer

Light must be available for reflection.

The vacuum eliminates scattering mediums, allowing the fluid's inherent color to be seen, but this requires an external light source to interact with the fluid for reflection or penetration to occur.

In the context of viewing blood in a vacuum, what is necessary for the true spectral properties of the fluid to dominate what an observer sees?

#Videos

What Color is Blood REALLY? (6 min version) - YouTube

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