Trail Renderer's colors don't apply to material

Trail Renderer doesn’t apply Colors I’ve specified to the material I’ve created from Trail Renderer’s Inspector view. Using GIMP, I tried to create RGB and Greyscale images with Transparent Alpha layers. Why is that?

Solution:

When importing RGB texture that will be used for something like a trail effect - import it as a Texture, not a Sprite(2D and UI), Texture Type.

When creating a material using that texture - set Shader to FX/Flare, not Standard.