Orthodontic treatment (braces) is the best if teeth are malaligned.
Just brushing won't help you with yellow teeth. Visit dentist for teeth cleaning.
Secondly if natural shade of your teeth is yellow, they will appear yellow only.
Next Steps
For more information
https://www.ar32.in
Health Tips
https://www.practo.com/healthfeed/10-dental-commandments-for-happy-teeth-40426/post