If you are going to learn how to get perfect pitch, then its essential that you understand how perfect pitch works.
Perfect pitch, is about learning to hear the subtle differences between each note in the chromatic scale. No, this has nothing to do with the intervals between the note. That is relative pitch. It is much more subtle than that. Every note has its own unique flavor to it (another word you could use is color) and when you can hear the difference between each note, and identify a note by its own color, you have perfect pitch.
You have probably experienced the flavor of notes before. For example, have you ever transposed a piece of music from one key to the next, or heard a song change key in its final chorus? It sounds completely different, right? Yes, it does sound higher or lower, but it is almost as if the song was given a different flavor. This is what perfect pitch is, only rather than hearing the differences between key signatures, you hear the difference between each note.
Try this, go to your primary instrument. (If you do not have a primary instrument, or are not sure of what to use, then use a piano.) Play a concert F#, then compare it to a C#. Be sure to not pay any attention to the interval between them, just listen to each individual note. You may notice that the F# sticks out much more and has a kind of edge to it while the C# has a more relaxed feel to it.
If you hear it only a little, but have a hard time pinpointing it, than that is okay. You may hear the difference very well, or you may not hear them at all. It can take some training to get used to. But hearing the difference is how perfect pitch works. It is simple as that.