Abstract. The color red has been shown to affect psychological functioning. In performance settings, it is associated with negative emotions, avoidance motivation, and cognitive restriction. Because red is frequently used in written performance feedback, we examined whether it represents an external form aspect that can adversely influence the perception of critical feedback by the receiver, independent of the verbal content of the feedback. To this end, we conducted a web-based experiment in which 171 participants performed an alleged attention test and were then given moderately critical feedback, including hints for improvement. Per random assignment, either some of the words within the feedback were presented in red letters or all words were presented in standard black. The participants’ subsequent evaluation of the feedback revealed that using red in the feedback caused the feedback to be perceived as relatively less emotionally positive. There was no direct effect of using a red font in how the feedback was cognitively perceived (i.e., how helpful, fair, or comprehensible it was). However, preliminary evidence suggests that using a red font indirectly had an adverse effect on the cognitive feedback perception, mediated via the emotional feedback perception. As a practical implication, red should be used cautiously in critical feedback in order to avoid compromising the functions of feedback.