is anything white?

Hey list members, is anything perceived by the standard observer as technically, absolutely white? If white is all colors, and assuming that means equally, it should be illuminated by the entire visible spectrum equally and reflect the entire visible spectrum equally (or be illuminated unequally and be unequally reflective in inverse proportion). Is there a combination of light source and material like that? Snow seems like a good candidate for a material, but illuminated by what? Our sun? Stars have different spectra. Is the spectral output of our sun at midday (on the equator during an equinox, or somewhere in the tropics at the right time of year) considered the reference "white" illuminant?