So I’ve decided on the Piet Mondrian dress and bought 40 to 50 3mm LEDs of each of the green, red and yellow colors. The battery is still of a concern but I’ve decided to go ahead and attach the leds according to the design and then calculate voltage and amperage needed. So far I sewed most of the green and red and once I am done I will go ahead and do some circuitry math and figure the best batteries kind and way (i.e. series or parallel) to attach them.
Side notes, I am using a conductive thread to sew leds together and it was somewhat difficult to find a 3 mm blue led that will ship in time so I’ve switched it with green.
wish me luck!