The way I remember which one is which, is that when I'm finished my Shellac service I think of it like getting to the finish line and getting a gold medal
When Shellac came out first, the bottles were very similar and because I wanted to know which was which at a glance, I would apply a little crystal on the top of the lid on the top coat.
I'm not sure what will happen with your client's nails, but at least you were honest with the fact that you made a mistake and she'll know to contact you if she has problems.
If they do last, just remember to allow a bit more time for removal, as the base coat contains easy release polymers and without this, I'm sure it will take longer to remove.
HTHs
Ha ha Angel I love the comment about crossing the finish line and getting gold. That made me laugh!
Also crystal on the top like like it, little but of bling for the bottle x