Why Is the Sky Blue in the Daytime but Red at Sunset?

Imagine you're playing with a flashlight in a room full of tiny balls. The light from the flashlight goes through the balls, and depending on their size, the light scatters differently. During the day, the sky looks blue because the small particles in the air scatter blue light more than other colors. But at sunset, the light has to travel further through the atmosphere before reaching you, so it scatters more of the red and orange light, making the sky look red or pink.