discolored [THES.] (US vs polychromate

discolored [THES.] (US

polychromate

noun

  • A salt or ion composed of multiple chromate groups 

adj

  • Composed of many colours 

How often have the words discolored [THES.] (US and polychromate occurred in a corpus of books? (source: Google Ngram Viewer )