Ok, so trying to tie this back to our problem at hand... we're not hitting the maximum rated current per led in our dumb strings. With the resistors used, it should be using a max of 20mA per color at 12V. I'm saying max of 20mA, because the red resistor is on the high side, probably only supplying 18mA. Further, a 100ct string is drawing under 4A, so the current per led is definitely under 20mA on average per color.
Chris brought up that we should only be using 66 bulbs because that should be 4A. If we add another 34 bulbs, that wouldn't increase the current per led. That would either cause our wiring to heat up and melt, or possibly damage our dsc, or cause a voltage drop near the end of the string and affect the colors of those nodes. Either way, it wouldn't over power and destroy the led.