As a guy with multiple autographed jerseys, here's a few of my favorite pens to use:
Black sharpie - Some people say these "fade" or yellow but I've talked to many people who say as long as the jersey uses legit tackle twill, you should not have to worry about it fading, yellowing, or even bleeding. This is what my Crosby is signed with.
Black Paint Pen- These work but needs some prep work. Honestly, I really couldn't tell the difference between these and regular sharpies. I had my McDavid signed with one of these.
Silver sharpies - Don't use these. They don't show up on dark numbers.
Silver deco - These or silver Prismas are the ONLY way to go for numbers. They pop out the best and look the nicest. See my Subban and Doan jerseys. Stay away from those sharpie paint pens. They don't work for some reason.
While you can find them cheaper elsewhere, these are what they look like.
Just out of curiosity, what jersey is it?