You're just telling us it don't work and don't supply full code, it's not easy to help you...
If the rest of the code works like I imagine, the first version of your code will fade as you like but because you're using the upper value 384 and not 256, you may get strange results. Depending on the timing of the rest of the code the fading may be so fast you won't see it but just a dimmed light as output. You see, without the full code there's a lot of imagination necessary to give you an interpretation.