Light yellow tends to disappear into white, so it usually needs a dark color to highlight it. Shades of yellow are visually unappealing because they loose cheerfulness and become dingy. Dull (dingy) yellow represents caution, decay, sickness, and jealousy. Light yellow is associated with intellect, freshness, and joy.
The definition of a frown is a facial expression indicating displeasure by drawing the brows together and turning the lips downward. An example of frown is the face you make when you are unhappy about something.
The definition of a scowl is a gloomy or intimidating look. An example of scowl is what an angry clown may wear on his face in a haunted house. Scowl is defined as to wrinkle the eyebrows to show disapproval or anger. An example of scowl is for a father to look at his daughter disapprovingly after she tells a blatant lie.