Question How to increase particle transparency (although start color and gradient editor have maximum alpha)

Correction: Contrary to the title, I would like to DECREASE particle transparency

I have a particle system that I intend to use for my torches, but I feel that the flames are too transparent, and I would like to increase their opacity. The problem is, I don't know how to do this, as all of the opacity-related settings in the editor have been set to maximum. I have a material for these particles, with this texture 2D set as the base map (first image). I would assume that the white area in the texture would be not at all transparent in the particles, and yet it is the opposite as I try to change the particles to a darker color (e.g the particles at the top of the particle system still have full alpha, but they are almost completely transparent. Is there any way to either adjust the texture (while still having transparency on it), or change a setting in the particle system so that my particles will have their intended color without fading out when they are darker colors?