As some of the comments mentioned, and you yourself have noted-- it's a little too bright.
Decent try though- A lot of people like to bash others for editing things, while I see it as the first step towards GFXing. Experimenting with and focusing on shading on a solid product lets you dabble in and exercise one aspect; instead of taking a leap forward and feebly playing with the whole palette of gfx skills at once, you're taking baby steps. I commend you, and wish you luck in your endeavors.
While I prefer to see original content as well, I encourage you to keep posting for feedback, and look forward to seeing you develop your own talent as you experiment with the other techniques that orbit GFXing. You'll get there if you keep at it.
Souizen was one of those guns I was experimenting with back when I was playing with PARAMs around December 2012; some people may have seen me PKing with it. There's a gold, pink, and black one somewhere out there.
I was surprised, most people responded to my purple MK23, and green/gold/red Famas.