I so Aalika's picture on Star Plus, and she is fair in real life, the Pratigya team are using make up all over her to make her look dark, yes Shaktia when he gave Kesar the milk said in the next life she must be born fair skinned and not dark. But Arushi is dark too, old Kesar, new Kesar and Arushi are all the same shade of darkness. Pratigya, Komal and Arushi/Pratigya's mother are fair, even Thakurain Sumitra is dark like the two Kesars and Arushi.
I think Shaktia was just using the skin colour as a cover of why he didn't love her, i think he was attracted to the modern type of girl, the one to stand up to him, i think he secretly admires Pratigya's guts to stand up to his family. Some people don't want an obedient wife, doormat, spit on her and she just takes it, the second wife Arushi spits on him and he doesn't mind...lol.
Even Thakhurain Sumitra and SS relationship, she will keep quiet when he tells her to shut up, but most of the time she is feisty (shows courage).