Or as it is said in glossario, Silvester is to say green, that is to wit, green in contemplation of heavenly things, and a toiler in labouring himself; he was umbrous or shadowous.    From Wordnik.com.  [The Golden Legend, vol. 2] Reference

“Envelop'd, shines, their umbrous veil dispers'd.    From Wordnik.com.  [The Metamorphoses of Publius Ovidus Naso in English blank verse Vols. I & II] Reference