#colorless

• Achromato- — A learned combining form (prefixoid) originating from ancient Greek ('achromatos') and used to form neologisms in physics, biology, or medicine. It introduces into the derived word the meaning of 'absence of color', 'chromatic neutrality', or 'lack of pigments'.
• Achromaturia — A pathological clinical condition manifested by the emission of completely colorless or pale urine, lacking normal urinary pigments (such as urochrome and urobilin). This phenomenon may indicate extreme dilution in diabetes insipidus, a severe inability of the kidneys to concentrate urine in advanced renal failure, or a massive and sudden intake of fluids.
• Achromasia — A general term designating the total absence of color or pigments within a structural medium. In medicine, it is synonymous with achromatopsia (total color blindness) or describes cellular and cutaneous depigmentation (lack of melanin); in optics, it defines the perfect correction of chromatic aberrations in a lens system.
• Achromic — Lacking color, discolored, or completely devoid of natural pigments; describing a cellular structure, plant tissue, or microscopic organism presenting a native transparency or chromatic neutrality.