We don't have synonyms for color index yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are colour index.
(N) :
Color index, as a geological term, is a measure of the ratio between generally dark mafic minerals and generally light felsic minerals in an igneous rock.
(N) :
Color index, as a geological term, is a measure of the ratio between generally dark mafic minerals and generally light felsic minerals in an igneous rock.