The colors you’re talking about are the beginnings of HI. You’ll begin to see them as you keep your eyes close, and will usually begin as a darkish purple. In fact, if you close your eyes right now you’ll notice that it’s not entirely black.
But rather than try to explain it in words, I’m going to point you to this WILD tutorial found on our knowledge base. It has some pictures giving you a rough idea of when and how you should see the HI. This WILD FAQ can also help you out if you have other questions.
The only other thing I would recommend for WILD is to attempt it 5 1/2 hours after you first go to sleep. HI will come on a lot quicker at this time.