New mortar doesn't match adjacent mortar.?

We performed brick infills in several apartment buildings. The bricklayer determined that the original mortar was standard gray color which was correct, however the mortar immediately adjacent to the infills has weathered, which exposes the minute pieces of aggregate and sand, giving it a more beige color. After drying, the new mortar really stands out. Is there a way to attempt to color the new mortar after drying; at least until it ages?