The red number
is the note that you should use as your guide when playing the
lick in other keys. In this case the red note is a G. This lick
is in the key of G major.
Because of the open string you will find this lick
more difficult to transpose into other keys. Here is how you would
play this lick in the key of A. You since there is not an open
string you will have to eliminate the pull of that was in the
original G major version.
3______ 3_______ 3_______
3______ 1_______ 1_______