Many highlighters have bright and fluorescent colors, and will emit fluorescent colors under the night light. The most common color is yellow, and other colors include pink, blue, green, orange and purple.

In addition, there is a dry fluorescent pen, which has no felt tip, but has a special opening to stick the fluorescent strip in the pen to the document, just like a tape. This kind of fluorescent pen is not as easy to clear as the traditional one.

Highlighter is a marker pen produced in recent years. It uses thicker and lighter ink to cover key parts for marking. After marking, it will not block the text at a glance. The fluorescent pen has fluorescent agent. When it encounters ultraviolet light (sunlight, fluorescent lamp and mercury lamp are more), it will produce fluorescent effect and emit white light, which makes the color look dazzling fluorescent. It is often used for office study.