Meaning
A solid orange square, part of the emoji version 12.0 colour set. It means orange and fills in the warm middle of colour grids.
People use it in gradient progress bars, mood trackers, pixel art and warning-level charts: “Energy today: 🟩🟩🟧⬜⬜” It also suits construction, traffic cone or autumn themes. Compare 🔶, which is the same colour in a diamond shape.