When Jalal picked the white dupatta today, I saw it as a sign of peace and purity and everything that others have already mentioned. But I also see it as something more than that: I see it as a blank canvas. When Jalal gave it to Jodha, he was offering her a second chance, a clean slate, a do-over. He wants to give their relationship a fresh start. I know Jodha seemed rude during the interaction, but she chose to color the blank canvas with pink, which can only be taken positively.
As Jodha said herself, the colors can be used to change relationships. Jalal brought white and she brought pink to their union. Instead of creating a murky blot, these two will form a beautiful light pink, which I can only assume symbolizes carefree happiness and love :)