It only affects color if you are doing a partial boil and it merely reduces the caramelizing (reducing the darkening effects of a partial boil). It has a pretty major impact on hop utilization, increasing the overall bitterness contributions.
Brewtarget lets you enter your ferment-able ingredients "late" and gives you an idea of the impact on hop utilization.
Late addition also reduces the energy necessary to maintain a rolling boil, since there's less mass in the wort. That's the primary reason I do it.
"Behold the rain which descends from heaven upon our vineyards, there it enters the roots of the vines, to be changed into wine, a constant proof that God loves us, and loves to see us happy." Ben Franklin