Early in our relationship — so, late 1980s or so — we were driving around, and Ulrika mentioned beige Volvos. And I said, “Beige Volvos? Do they even make those?”
Whereupon we saw about five beige Volvos in the next fifteen miles. (This was on an LA freeway. That’s a short distance.)
“Beige Volvos” has become our shorthand for something that is ubiquitous, but invisible, until your attention is called to it. (I think there’s a different term for it, but this is ours.)