achromaticity

from WordNet (r) 3.0 (2006)

achromaticity
    n 1: the visual property of being without chromatic color [syn:
         {colorlessness}, {colourlessness}, {achromatism},
         {achromaticity}] [ant: {color}, {coloring}, {colour},
         {colouring}]

from The Collaborative International Dictionary of English v.0.48

Achromaticity \Ach`ro*ma*tic"i*ty\, n.
   Achromatism.
   [1913 Webster]