Hi! Well, for me, I am usually not picky about matching natural stones for things like this (e.g. 20 motif). However, for earrings, since there are only two, I would have expected a better match. If these two motifs were part of a 20 motif, then I would keep the 20 motif as it would not be a big deal and the uniqueness gives the 20 motif character.
However, in the case of an earring set, I would want it to match. That's the whole point of earrings, a "matched set" the trade's terminology when buying stones for earrings. The emphasis is on how perfectly they match.
Hence for me, I would not accept them,and I would not hesitate to tell the SA they are earrings, just two motifs, and they are not even matched.
Instead of ordering a new set (another crap shot), I would pick the motif you like the best and ask if VCA can replace one of the stones to match the stone you like. This would be the easiest solution and most likely what VCA will do given this is a MTO.
Replacing one stone is easier too; they do not need to make a whole new earring.
Also, to me, the fact that you had to post this question on TPF says you are not in love with these earrings. First impressions are usually correct, and there is no point in trying to convince yourself to keep them. It should be love at first sight, which it is not.
My vote says ask for a new motif.. easy fix. That's my two cents. Hope this helps in your decision.