We describe the immature and mature morphs of Ischnura saharensis, based on individuals from Gran Canaria (Canary Islands, Spain), and report population morph frequencies for this species from Gran Canaria and Morocco, and for I. genei from the Mediterranean islands of Sardinia and Sicily. We found that I. saharensis has a wide range of colour variation in females, resulting from the combination of three colour morphs with ontogenetic colour changes. Mature androchrome females have a bright green thorax, very similar to males, but some are bluer than males when immature. Gynochrome females are either greenish-brown when mature (infuscans morph) or ochre-brown (aurantiaca morph). Ischnura saharensis from Morocco showed a preponderance of androchromes in one population and aurantiaca in the remaining three. The infuscans morph was the rarest. In contrast, androchromes were slightly more frequent than the other morphs (34–40 %) in Gran Canaria, and the proportion of infuscans and aurantiaca was very similar (30–34 %). In the case of I. genei, the aurantiaca morph was the most common in all populations (58–77 %). No infuscans females were found in Sicily, but these represented 8–23 % of females in Sardinia. Even when the infuscans morph was the rarest in I. saharensis, this morph was in all cases over-represented among mating pairs (significantly in one population). In I. genei, the aurantiaca morph was the commonest and the most frequently found mating (significantly in one population). Our results suggest that I. saharensis and I. genei resemble I. elegans in their wide variation of population frequencies between regions, supported by the fact that androchrome females mate at low frequencies.