Can't Fix A Bad Quality Cap

I was trying to make some icons using some pretty bad quality caps and I am having lots of trouble improving it. I have been through the memories tried everything and nothing works. The sharpen filter makes it to pixelated and badly colorized. The blur tool makes it a bit too blury. Some wacky combination of the two still doesn't work. So, I was wondering if I could get some help with it. If you have any ideas or know how to do it, I would love to hear them. This is what I'm working with:



So, if you know how to fix it, please tell me. Thank you very much!