1 Introduction Animal colouration is a key trait in organismal biology, involved in natural and sexual selection, ecological traits like competition, and communication (Caro and Mallarino 2020; Endler and Mappes 2017; Hutton et al. 2015; Orteu and Jiggins 2020; Rudh and Qvarnström 2013), allowing researchers to investigate various evolutionary and ecological questions. Much is now known about the genetics of colouration using model systems such as mice (Kingsley et al. 2009; Wooldridge et al.
