The sky isn’t just blue — airglow makes it green, yellow, and red too The sky looks blue on a sunny day. But at night, we can see the faint glow of its true color.

Most often (though this can vary by manufacturer), the red button switches between uppercase and lowercase letters, the green button deletes the last letter, the yellow button changes the input ...

The red, blue, green and yellow cards are a family favorite – Mattel sells 17 decks of UNO every minute, according to 2021 data. But like many card games, UNO has evolved and rules have changed ...

The yellow light would not come into play until the 1920s. William Potts, who was a police officer in Detroit, is credited for designing the first three and four-way colored traffic lights.