Right here, and it's not a silly question. A figure 8 mic WILL sound darker off the back side BUT ONLY because you're listening to the sound thru headphones. On speakers, there's no difference. The reason has to do with combining the negative signal from the mic with the positive signal of your natural voice resonating in your ears. It cancels out the high end, but it's not recorded that way.
Record both sides of the mic and play it back; I doubt you'll hear much, if any, difference.