The letter X in all it's various forms through history. I put every X word in the dictionary behind the letters and used the color yellow, because the word xanth means yellow.
"A shrewish, tart-tongued woman is often called a Xanthippe, after the wife of Socrates, who filed this bill of particulars in a spectacularly venomous fashion."
~Morris Dictionary of Word and Phrase Origins
I couldn't help myself!
I will leave you with this poem.