Source Voltage = 5 V (USB thingy)
red =1,2–1,8 V
green = 3,0–3,4 V
If i think about these values, I dont even know what it tells me.
current ^= water flow, think liters/second
voltage ^= water pressure in your pipeline
resistor ^= diameter of your valve (more OHM -> smaller diameter)
U = R*I (volt= ohm/ampere) (higher pressure -> more water / narrower valve -> less water )
need a specific amount of water per minute? use a "calculated" valve.
-> U/I = R
i can't think of an analogy to the voltage drop (anyone?), but effectively it reduces the voltage that you use for the calculations.
if the voltage drop is 1V use 4V instead of 5V to find the right valve.
it sounds as if you're going to drive your LEDs in parrallel in order to light them up individually. so you can calculate your values independently from each other.