The shape of the yellow area of the dorsal forewing(just visible here) and the lack of a cell spot leads me to conclude that this is Eurema tominia nabalua, rather than E. nicevillei nicevillei (Reference: Shirozu and Yata).
It is E. nicevillei.
Often in Eurema the FW cellspot may be missing.
The shadow of the HW black border can be seen & it is very narrow.
It closely matched this E. nicevillei from Ko Samui. http://www.samuibutterflies.com/02_i...nicevillei.jpg