Beige flagging is calling out small, weird, or mildly off-putting traits in a partner that are not deal-breakers (red flags) but are not strengths either. "He only listens to film scores; total beige flag." Light-hearted dating TikTok vocabulary. Not concerning. Helps young people talk about compatibility. If your kid uses it constantly, ask them where they first heard it, not to police their speech but to understand which online community they are in.