I am getting braces in 5 more days. but i am quite afraid that after i remove my braces, it will have braces marks because my teeth not very white now?

It's up to you: Teeth have white decalicification spots & decay if you do not keep them clean while you have the braces on. You have to brush & floss properly & often enough as well as avoid foods and liquids high in refined sugars & acids. If you do that, you will have the same looking teeth as when you started with, except they will be STRAIGHT & better looking. You can then have your teeth profess'ly whitened

Not from braces: Braces don't scar teeth. Bacteria do. Ask your Orthodontist for specific instructions, and follow them to the letter. Keep teeth immaculately clean (braces shine when they're clean) to prevent scarring next to the braces. Don't cheat, don't eat hard/sticky/chewy foods that can partially dislodge braces to prevent scarring behind the braces. Follow instructions to the letter, you'll be OK.