Studies have also shown that certain colors can have an impact on performance. No one likes to see a graded test covered in red ink, but one study found that seeing the color red before taking an exam actually hurt test performance
While the color red is often described as threatening, arousing or exciting, many previous studies on the impact of the color red have been largely inconclusive. The study found, however, that exposing students to the color red prior to an exam has been shown to have a negative impact on test performance.
In the first of the six experiments described in the study, 71 U.S. colleges students were presented with a participant number colored either red, green or black prior to taking a five-minute test. The results revealed that students who were presented with the red number before taking the test scored more than 20% lower than those presented with the green and black numbers.