I recently had a root canal. This is my second temporary crown but it's very dark. Will it stay this way until my permanent one?

The temporary crown will stay whatever color it was during the crown preparation phase. Not to worry though. The laboratory along with your dentist has the skill to match the porcelain on your permanent crown to your natural dentition

Root canaled teeth often do darken over time and if you had a silver filling that can also darken it as well. Your temporary will not mask out the darkness as well as your crown. Temporary crowns are made of composite whereas most crowns are made of porcelain. Porcelain crowns can mask out the darkness better. Unfortunately, if your root structure is dark and you have translucent gums then you can see darkness at your gum line. No crown can mask that out. Hope this helps and good luck.

Hi. Without a photo it is difficult to give you accurate advise.  However, root canaled teeth normally discolor and since the temporary crowns are more translucent it is difficult to fully cover the discoloration in the temporary phase.Best,Dr. Maddahi