Maybe it's because they're transparent. Maybe it depends on what they're eating this week. Maybe it's where they've settled. Maybe they're akin to mood rings: whatever the reason, the orange-striped green anemones, Haliplanella lineata, in my tank are never the same colour twice in a row.
|Open, showing mouth lining. Pinkish today.|
|Almost closed. Just the slightest hint of orange. And the green base is blue.|