The Collaborative International Dictionary of English v.0.48:

Chrome \Chrome\, n.
   Same as Chromium.
   [1913 Webster]

   Chrome alum (Chem.), a dark violet substance,
      (SO4)3Cr2.K2SO4.24H2O, analogous to, and crystallizing
      like, common alum. It is regarded as a double sulphate of
      chromium and potassium.

   Chrome green
   (a) The green oxide of chromium, Cr2O3, used in enamel
       painting, and glass staining.
   (b) A pigment made by mixing chrome yellow with Prussian
       blue.

   Chrome red, a beautiful red pigment originally prepared
      from the basic chromate of lead, but now made from red
      oxide of lead.

   Chrome yellow, a brilliant yellow pigment, PbCrO4, used
      by painters.
      [1913 Webster]

WordNet (r) 3.0 (2006):

chrome alum
    n 1: a violet-colored salt used in hide tanning and as a mordant
         in dyeing