I tried making my own vanilla extract a few months ago. Normally, it should be pretty dark (almost black). Mine isn't, as you can see:
What I did was (after sterilizing it) filling a 250 ml (about a cup) bottle with vodka. I also cut up some (mostly seeded) vanilla pods, I think 4-5.
My guess is that there isn't enough vanilla in it. I'm planning on putting some more in. Is that the proper way to save this half-extract? Are there any downsides to adding new pods now?