Well, spring is associated with birth/rebirth, summer with growth, fall with weakening or harvest, and winter with death. Also, for the Goliath ritual:
A. Have the blackness come from mushrooms, which the shaman eats before tattooing the infant. Spirit of the gods and all that.
B. Have the empty space be on the back of the goliath, not the front. This means that the Goliath can decide his own name, but he still needs the tribe to tattoo it on him. It has all sorts of nice symbolism and stuff, plus (more practically) it reinforces the shamans hold on the tribe, since the shaman's the most likely to understand how to tattoo somebody.