Very nice picture.
:shock: I don't expect that the yellow/orange is so bright !!
Fred & Oli : it seems that inner mouth coloration come from the behaviour's evolution of this genus. Due to the durnial activity of them, mouth coloration appears first with dark blue and evolved in some species in yellow. Like Fred said it's a benefit to affraid diurnal predators. This hypothesis was developped by J. MELVILLE, J.A. SCHULTE, A. LARSON.
The connection between coloration and diurnal behaviour is done by the ancestral evolution of a dark mouth coloration which can't affect seriously nocturnal predators.
This kind of attribute appears in some other species of the diplodactylinae (Saltuarius cornutus which is arboreal too).
Does they have the same (kind of) predators ?
Some interesting precisions can be found in the article, which was online a few months before, "A molecular study of phylogenetic relationships evolution of antipredator strategies in Australia Diplodactylus geckos, subgenus Strophurus"
Kei_on : I think so. S.c.ciliaris have dark blue mouth and S.c.aberrans have yellow mouth. To my mind, there are only S.c.abberans and S.taeniatus which express yellow mouth color.