Color in Advanced Lightning Effect doesn't seem to be working correctly

I sent a clip over from Premiere Pro to After Effects.  I added Advanced Lightning to that Composition (I did it on top of a Black Solid actually).

So, first of all, when the Lightning flickers, it keeps on flickering WHITE and GRAY.  I don't want it to flicker GRAY.

But also, I tried changing the Lightning color with the Curves effect, but the Curves effect is doing absolutely nothing to the Lightning color.

I'm thinking I must have a setting that's affecting this, but I can't figure it out.  If anyone has any insight it would be greatly appreciated!!