¶An idiom is a figure of speech and does not mean what the word or phrase says or reads.For example "It''s raining cats
and dogs". That expression does not literally mean cats and dogs are falling from the sky, but it means it is raining really hard. Another example would be "in the limelight". This idiom, like a few others, does mean some what how it sounds.
¶"limelight is actually a type of stage lighting once used in theatres and music halls" (Wikipedia limelight). Goldsworth Gurney was the name of the man who discovered the limelight effect in the 1820s. Scientifically, limelight is an intense illumination created when an oxyhydrogen flame is directed at a cylinder of calcium carbonate (limestone), which can be raised to white heat without melting. The light is produced by a combination of incandescence and candoluminescence (Wikipedia limelight).
¶This is where the expression "in the limelight" came from. Its another word for spot light and center of attention. "In the limelight" applies to all types of people, but in today''s society it mostly goes for celebrities in the media.