Restart the whole thing on a white background, then do the shape of the wrenches in black. Afterwards, give it some sort of base color (in this case green, but I'd be happier with gray used for the sake of realism) and add details on these two object that are found on actual wrenches aswell. Use a picture for reference if that helps. Once you're done with adding the pieces of detail, color the individual parts. If you're done with that, imagine there's a sun glowing on one part of the icon, let's say the top right corner. Do a few lines on the lower left part of the wrenches with dark, which are not in touch by the imaginary sunlight, that's the shading. Use a lighter green tone when doing the areas close to the sun. Those are the highlights. Fill the background with black and resize, you might optionally want to add a glow too. Give it a few tries or read tuts if you're not cerain on things.
Basically.
