Here are the various descriptions of color I've written in my notes for 6572. All are separate observations, starting in 1992, and were made with my lowest available magnification, which ranged from 83x to 106x:

No color mentioned (20" f5)
Bright Green (20" f5)
Bright greenish-blue (20" f5)
Robin's egg blue (28" f4)
Jade (28" f4)

These color descriptions span 22 years, but since I've listed them in chronological order they don't suggest I'm loosing color sensitivity, thank goodness. But the difference from bright green to Robin's egg blue does suggest that observing conditions play a role in how I've perceived 6572's color.