This is a great try. The shading is a bit off and the color palette is displeasing. Not that the color choice is bad, I like the red, I mean the overall palette changes.

Also, the curving of the body(ie: the boobs) will also change how the suspenders will be shaded in that area because the way the light hits it will be different in that area.

If I would pixel shade like you have here, I usually do my shading part with contrasting colors and I don't even use my palette at this point. It might seem strange but I can see where I need more darker shading here, lighter there, ETC.