I use vertex sprite to make a fire. When I use a colored fire texture, it works fine. I can see the center of the fire is bright, and the eage is dark, because I put more vertex in the center. But when I use a graystyle texture and set vertex color to red, I can't see the fade effect, everywhere is the same red. I use Blend.One as the blend option. Please help me to solve this problem. thanks

vertex color in particle system