Ohhh, okay, I think I might've misunderstood your question. Anyhow, I fiddled around with Photoshop and the glow tutorial that's already been uploaded (I'm assuming you're familiar with this).
Basically what you have to do is drag the original marking over top of the glow layer. With the glow tutorial, the copy of the original marking is the one that becomes the 'glow', and you have to put the original non-glow marking on top of the 'glow' copy, just like how you'd drag the files around to get, say, Arach to show up on top of Celestial.
I'm assuming
this is what you're encountering right now (note how 'Arach copy' is on top)
But after dragging the original marking on top, it looks like
this, which I think is the effect you wanted? I have the body and the Arach set to more or less the same color just to make the green glow pop, but you can totally assign a different color to the body and markings. If I've got it wrong again, my bad. P: That's the best I can come up with.