Open margin? Have already had one set done, cemented and taken off due to wrong color within the last three weeks? Help

Basically you need to ask the dentist to remove the excess cement and see how it looks under magnification. Treatment of this nature should always be done under high magnification and I would question any dentist who claims to see margins and marginal gaps under 4-5x magnification. 
The open margin, if there is one will show up easily in a few years as it yellows and takes stain where a closed margin would not, so it is not something that can be hidden. 
Kind regards
Thomas Dey, BDS, MSc

Looks like the junction of the ceramic to the tooth (this is usually sealed with veneer cement and polished). But.....Your gum tissue is uneven and might only be an issue if it shows when you speak or smile. Your dentist can measure the gum pocket and determine if there is any underlying gum issues complicating the look of your veneers.

lvaughn,It sounds like you have discussed the problem with your dentist, but she has not seen it just yet.  It is difficult to tell from the size of the picture exactly what is going on, but cement around veneers immediately after placement is common.  Your dentist is right in that it can be removed and polished out. An open margin could be a possibility, but less likely.  If it is an open margin, the easiest thing to do if it is very small and inconspicuous might be to back fill with a resin or something like that.  Otherwise, the veneer could be redone, but that means starting over by removing the current veneer and going through the whole remake process.  Definitely something for you and your dentist to work out.  Again, It is more likely that it is cement though.Warm Regards,

Hi:It's difficult to 100% tell, however, your dentist is most likely is correct.  It can be polished.Best,Dr. Maddahi