Are both females? Just wondering why the females are so colourful in butterflies. Are they toxic?

The two images are from the same individual, just showing the dorsal & ventral side of the wings. It's hard to tell whether males or females are more colourful (i.e. beautiful) in butterfly world. It depends on species. In some species, males look totally different from females that people may misunderstand as different species. While in other species, males and females look almost the same. For Purple Sapphire, you can't tell the difference on the ventral side. But when the dorsal side of the wings can be observed, males show blue/violet shiny pattern while females do not, as in this photo.
Most butterflies are not toxic (as least to the predators), except the ones from Family Danaidae (斑蝶科). Caterpillars of this family feed on poisonous plants so that a high level of toxic substances are stored in their bodies.