grays on trays
n. Older adult snowboarders.
Snowboarding is the fastest-growing sport among the 18- to 25-year-olds advertisers covet, and even has increasing appeal among older adults — or "grays on trays," as snowboarders call them.
—Mark Robichaux & Roger Thurow, “Awesome Dudes Tell Why They're Totally `Sick',” The Wall Street Journal, February 13, 2002
1997 (earliest)
Every week he gets 41-year-old guys like me signing up for initial snowboard lessons. They call us "grays on trays."
—Jim DuFresne, “Spills aplenty greet novice snowboarder,” The Grand Rapids Press, February 01, 1997