Is the material itself blue, or is it structural color? I ask because I’m aware (as far as I believe) that hydrogen gas is colorless, and the solid hydrogens I

Is the material itself blue, or is it structural color? I ask because I’m aware (as far as I believe) that hydrogen gas is colorless, and the solid hydrogens I’ve seen certainly aren’t blue. Though structural color is a rabbit hole I’ve had to go down recently for an application (where the component materials have no color), so it wouldn’t surprise me that some materials at ridiculous levels of purity get interpreted as certain colors only because of the interference of light through the material.