Invert Matte Step by Step

In response to Alex and Dee, here's the breakdown on how to apply the invert matte in the Glow FX to add an 'explosive' effect. Apply the following to your already existing scene set-up

Step 1. Create a new drawing layer ABOVE everything you want to affect and draw something. Anything - a brush stroke outside the camera view area will work. Add a GLOW effect to this new layer.

Step 2. Click on the GLOW layer to bring up the layer properties panel. make your blur RADIAL and make your Blur Radius 2 or 3. Tick 'Invert Matte'

Step 3. In the same panel play around with the color values, and push the alpha to a value of 255 for maximum effect (it's actually best to do this with the scene in render view, so you can see what you are doing, and how the effect is working)

Also - create keyframes to change the color values in the timeline for a 'flashing' explosive effect

And that's it. You can also us this process with the SHADOW effect layer to tint your entire scene