The Dark Blue Tiger Butterfly is native to South and Southeast Asia. Both the Blue Tiger and the Dark Blue Tiger are common over their overlapping ranges.
The Dark Blue Tiger (above left) is not only noticeably darker (more brown) than the Blue Tiger (above centre) but certain key features of its pattern differ (ringed). Both are males with a "pocket." The butterfly above far right is a female (no pocket flap, more blue) and appears to have features halfway between the two -- so probably a Scarce Blue Tiger from India.