To turn red means that something becomes red in color. Often used for faces that blush from embarrassment, anger, or exertion, or for a traffic light.
NEVER try the local thing. You know why it's local? Because it's shit, that's why it's local. You eat it, you'll become one of them, you'll turn red and start spouting bigotry and eating tweed with lamb fat dribbling down your chin, don't go near any of that stuff. Dylan Moran
As the awards air on ITV, landmarks across London, including the London Eye, BT Tower and County Hall, will turn red, white and blue in celebration of this year’s winners. Source: Internet
Crawford recalled that, if he went three for four on a day when Cobb went hitless, Cobb would turn red and sometimes walk out of the park with the game still on. Source: Internet
The solutions of these salts turn red when cooled below −60 °C, owing to the formation of the Imain cation: :2 Imain ⇌ Imain Under slightly more alkaline conditions, Imain disproportionates into Imain and an iodine(III) compound. Source: Internet
It'll turn red when you're late. Source: Internet
Once the due date has come and gone, it will turn red. Source: Internet