Just do runs of the easiest place you can that Kefka named, and make sure to destroy all the boxes.
One more thing, if you're online, the color barriers are only a couple PD's (1? 2? maybe 3?), just don't trade your PD's for Monomates!
16, actually, IIRC.
Support and Recovery barriers cost one PD, though.
And I repeat, don't hunt anything in Normal difficulty.
no u must trade photon drops for a amplifire at the shop or search on hard-ultimate mode
You can't buy the amplifiers at Gallon's Shop, those you have to hunt (boxes). You can only buy the barriers with PD's.