According to Wikipedia, 'Indian summer' can be used metaphorically to refer to a late blooming of something, often unexpectedly.
Meteorologically, Indian Summer is a period after a killing frost in which there is a revival of summer temperatures. The colors are the golden, red, orange and green shades of autumn, along with bright sky blue.
And what could be better for vintage lovers than late blooming?
Vintage 70s Don Luis Espana Dress from Poppy's Vintage Clothing
Vintage 1950s 60s Double Strand Glass Bead Choker Necklace available at Aaralyn's Velvet Dragonfly
A "fall colored" dress from the private collection of Linn's Collection
You can find more fabulous vintage items from more sellers at the VINTAGE FASHION GUILD WEEKLY PARADE!