Delilah needed to be different from the rest of them culturally because of the story, she also needed to have a transition from her original job as a courtesan to her stable relationship with Samson.
Samson's design is based on influences from Egypt (i.e. Exodus), and on some desert/warrior motifs as well. He's meant to look tough but not the same as the philistines. His headdress allows us to cut off his braids every night and replace them in the clasp for the next day.
The Philistines are meant to be like executives that have had to live in the desert, cannibalizing their clothes and tools. However rough and post apocalyptic they live, they are in charge and so want to appear to be strong. They hate Samson because he challenges their power.
I still need to design for the extras of the cast, three women who will dance and help create the scenes. They are philistines but less executive than those with lines. I'll post them as soon as I can.