purple patch

noun

Also called: purple passage a section in a piece of writing characterized by rich, fanciful, or ornate language
slang a period of success, good fortune, etc

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012