{Reference Type}: Journal Article {Title}: Over the rainbow: Guidelines for meaningful use of colour maps in neurophysiology. {Author}: Cooper PS;Baillet S;Maroun REK;Chong TT; {Journal}: Neuroimage {Volume}: 245 {Issue}: 0 {Year}: Oct 2021 9 {Factor}: 7.4 {DOI}: 10.1016/j.neuroimage.2021.118628 {Abstract}: Visualization of complex data is commonplace in neurophysiology research. Here, we highlight specific perceptual issues related to the ongoing misuse of variations of the rainbow colour scheme, with a particular emphasis on time-frequency decompositions in electrophysiology as an illustrative example. We review the risks of biased interpretation of neurophysiological data in this context, and provide guidelines to improve the use of colour maps to visualise complex, multidimensional data in neurophysiology research.