Hey now, don't sell yourself short. I think it looks very good!
The yellow border looks much better but I think it could look very good with a filled interior of black. Basically the same way you did the handles of the hammers but within the entire yellow section. It would definitely help it pop out a little better by contrast. To be honest, I don't think it really needs it, but if you're looking to add a certain something, and you don't know what it is, that might help.
Keep up the good work!
DoW