I am writing in response to an article by Bolton, Rollinsand Griffith (2015) entitled ‘The danger within: the roleof genetic, behavioural and ecological factors in populationpersistence of colour polymorphic species’ that wasrecently published as an Opinion under the NEWS ANDVIEWS section in Molecular Ecology. Bolton et al.(Molecular Ecology, 2015, 24, 2907) argue that colour polymorphismmay reduce population fitness and increaseextinction risk and emphasize that this is contrary to predictionsput forward by Forsman et al. (Ecology, 89, 2008,34) and Wennersten & Forsman (Biological Reviews 87,2012, 756) that the existence of multiple colour morphswith co-adapted gene complexes and associated trait valuesmay increase the ecological and evolutionary successof polymorphic populations and species. Bolton et al.(Molecular Ecology, 2015, 24, 2907) further state that thereis no clear evidence from studies of ‘true polymorphicspecies’ that polymorphism promotes population persistence.In response, I (i) challenge their classifications ofpolymorphisms and revisit the traditional definitions recognizingthe dynamic nature of polymorphisms, (ii)review empirical studies that have examined whetherand how polymorphism is associated with extinction risk,(iii) discuss the roles of trait correlations between colourpattern and other phenotypic dimensions for populationfitness and (iv) highlight that the causes and mechanismsthat influence the composition and maintenance of polymorphismsare different from the consequences of thepolymorphic condition and how it may impact on aspectsof ecological success and long-term persistence of populationsand species.