origins plays up the fact that their stuff's purely nature-based and without a ton of chemicals. the typeface, which i believe to be Cyan Sans Bold, is stark, simple, and sparse.
philosophy is similar, though not so focused on nature. the packaging on philosophy products consists solely of copy. as a copywriter, i was always taught that too much copy was BAAAD. but for philosophy, it works. the products possess a clinical expert's feel, yet the look is clean and beautiful. the typeface is most likely Janson URW T Light. (it also resembles Indigo P Regular, or even Garamond MT.)
i'm just wildly guessing here, but the deva logo typeface looks uncannily identical to the one designers love and loathe: Helvetica. deva's products are designed specifically for curly hair, so the plain lettering might suggest simplicity and ease--something curly girls desperately need with hair care (trust me. i have curly hair, so i know).