This is the simple blue plasma glow I use on my Imperial Plasma weapons, basically any plasma weapon that's not had some chaos or purposeful colour alteration, it's inverted, so the shading is light, and the highlighting is dark.

1. Undercoat is irrelevant mine is normally Mechanicus Standard Grey, but your basecoat is a healthy covering of Baharroth Blue at least 2 thin coats as is the way.
   This is for both the coil itself and in any exhaust ports indicator holes or the barrel (make a shallow concavity on my plasma guns)
2. You can use White Scar but Warhammer whites are horriffic, so Dead White 1:2 Contrast Medium and wash into the coils along the sides without joining at the top of the coil. Say the bottom two/thirds.
3. Now do a second coat of Dead White 1:2 Contrast Medium along the bottom of the coil, Say the bottom one/third.
4. Highlight the coil ribs with Baharroth Blue , you can do a very light dry brush if you're careful.
5. light Baharroth Blue 1/1 Ahriman Blue Highlight the coil ribs making sure not to completely remove the previous step. Without drowning the non-coil holes put a bit of this around the inside rim of each hole.
6. Ahriman Blue highlight on just the top one/third of the coil. Also a little around non-coil holes put a bit of this around the inside rim of each hole between the above step and the corner rim.
7. Add Stegadon Scale Green 1:4 Contrast Medium Around the coil casing, that is the area around the coil or the holes, that is not actually the coil itself. You can also do this to any part of the final mini you with to have a bit of light be glowing onto. typically the hands, up the arms or chest.
8. A second coat of Stegadon Scale Green 1:4 Contrast Medium on coil casing directly around the coil inside the area of the last step.
9. Stegadon Scale Green 1:1 Ahriman Blue highlight on the edge of the casing around the coil and the holes/barrel.