chrominance
Concise Oxford English Dictionary © 2008 Oxford University Press:
chrominance /ˈkrəʊmɪnəns/
▶noun the colorimetric difference between a given colour in a television picture and a standard colour of equal luminance.
– origin 1950s: from Gk khrōma ‘colour’, on the pattern of luminance.
'chrominance' also found in these Oxford entries:

