A color flashes briefly. Recreate it with the hue, saturation and lightness sliders.
Everyone gets the same colors. Join with a QR code; results sync by sound at the end — no internet needed.
Set the number of rounds, then show the QR code for the other players to scan.
Point the camera at the other phone's QR code.
Add ColoGuess to your home screen for full-screen play that works offline — no internet needed.