My interpretation of Crime & The City Solution's Rose Blue.

Introduction and Riff:
e-----------|
B-----------|
G-----------|
D-------2---|
A-----2-----|
E-0-3-------|

Those four notes: E, G, B, and E (on your fourth string) are played in succession then 
played backward in succession from your D's E to your open E on your sixth string twice. 
When you play from your open E again you add these notes, looking like this:

e-------------------|
B-------------------|
G-------------------|
D-------2h3p2(v)----|
A-----2-------------|
E-0-3---------------|

You then repeat all over again.

When Simon sings "The hollow that I parted on..." you only play the riff as follows from 
your open E with no backwards playing. However, what follows next is how I go about it. 
You can play an Am chord or F#5 power chord (with double root or no double root).