itch.io

For whatever reason you can't set a texture to import as BGRA, but you can create a new texture in BGRA format and carry over the pixels to it, like so (also seen in test project on git):

Texture2D ConvertTexture(Texture2D texture, TextureFormat format) {
    var tex = new Texture2D(texture.width, texture.height, format, false);
    tex.SetPixels32(texture.GetPixels32());
    return tex;
}