You wear it as a disguise at Giza, where the diggers (and Vince) mistake you for one of their fellow tomb robbers.
You give her the Blue Lily from Blue Nile Falls in exchange for the turban.
Get the Egyptian Blue Lily from the left side of Blue Nile Falls, and trade it for a turban at Nabooti.
Vince is the man by the tent and he doesn't have a turban on
Put on your turban.
Get the "desert turban" by picking the Blue Lily at the Blue Nile Falls. Swap it for a turban at Nabooti. You will need to wear it when you travel to Giza.
Take the Lily to Nabooti and to the trader who specializes in plants and flowers.
Get the blue lily from the Blue Nile Falls, and swap it for a turban at Nabooti.
Once you get the blue flower at Nile Falls, you can bring it to Nabooti island and trade it for a black turban. Then fly to Giza and put on the turban, the tomb robbers will think you are one of them and give you a shovel.
Take it back to Nabooti and trade for a turban (you might want to wear it at Giza).
Find the Egyptian blue lily at the top left side of the Blue Nile Falls. Take it to Nabooti and the middle trader will give you a turban for it. Wear it when you go to Giza.
The Blue Lily is at the left side at Blue Nile Falls. You can swap it for a desert turban at Nabooti. Wear the turban to get past the tomb raiders at Giza, and get a shovel.
Find the Egyptian blue lily at the top left side of the Blue Nile Falls. Take it to Nabooti and the middle trader will give you a turban for it. Wear it when you go to Giza.