大盲位转牌冷跟注彩虹面（BB Turn Cold Call Rainbow）

This term is a combination of multiple poker concepts:

• BB (Big Blind) : Position, referring to the big blind player.
• Turn : The fourth community card after the flop.
• Cold Call : Calling a raise without having any chips invested (or only the blind), usually occurring after a raise and re-raise.
• Rainbow : Three cards of different suits on the flop, but here because "Turn" is included, it generally means all four community cards (flop + turn) are of different suits, or specifically that the flop was a rainbow and the turn did not change the suit distribution.

Typical scenario: The flop is a rainbow (e.g., ♠♥♦), and the turn brings a fourth suit (♣), creating a "rainbow turn." At this point, the big blind player checks the flop, then on the turn, Opponent A bets, Opponent B raises, and the big blind calls directly without favorable pot odds. This play usually indicates the big blind holds a strong draw (e.g., straight draw) or a strong hand like a set, intending to slow-play or bluff.

Since "Rainbow" is often used for the flop, its appearance after "Turn" here may refer to the board remaining without any flush draw possibility throughout. This term is not a standard poker term; it's more of a colloquial expression used by players to describe a specific situation.