I'm very new to latin and was trying to use the phrase "Pillar of Truth" as a title. I was sure "Columna de Veritas" was correct but "Columna Veritas" has also been suggested. Which is correct? Thanks in advance.
Neither, I'm afraid. You need to change "truth" to the genitive case for this. So, either Columna Veritatis or Veritatis Columna, depending on your stylistic tastes. For a comparison, the previous pope issued a document, Veritatis Splendor, "the Splendor of Truth."