Ales Rarus

Here's an article about reaction to teachers dropping red correcting pens in favor of purple ones.

According to the teacher, red may be a startling color, but the important thing is that it gets results. Jago notes, just as a red stop sign is the best way to get drivers to pay attention to a potentially dangerous intersection, making red marks on a pupil's paper is the best way to get the student's attention focused on a learning or comprehension problem that needs to be corrected.