This is very interesting. So Sri Lankans are more similar to Bengalis, genetically. This explains the variance in their facial phenotype to Tamils, tho both are equally beautiful in their own right.
I actually find the darker skinned Indians to be very attractive, personally. 2 semester ago we had in my university a South Asian festival that celebrated dances from parts of South Asia, there were Pakistani dancers, Bangladeshi, Punjabi, Sri Lankan and then there was one dance performed by one Tamil Indian student -- I believe the dance she performed was called -- Bharatnatyam. The elegance of her form, her skin tone, and the jewelry and regalia that adorned her body was ethereal.
Beautiful.