“Males that achieved brighter stripe coloration were more likely to approach their opponent, and those that attained brighter head coloration were more likely to win fights; speed of head colour change was also an important predictor of contest outcome”…
https://royalsocietypublishing.org/doi/10.1098/rsbl.2013.0892
https://royalsocietypublishing.org/doi/10.1098/rsbl.2013.0892