Vaseline helps to product your lips from sun. It is mostly used for moisture loss lips and chapped lips. It also used to soften the nail cuticles. Vaseline will not be useful if you severe dry lips. But if your lips are pigmented due to lack of moisture, then Vaseline can help you by moisturizing lips.
If you born with brown lips, Vaseline will not going to make it pink. As it comes with small packet, you carry it any over. The product says itself that apply it for every ¾ hours. We need to apply it again and again. Vaseline works if you have pink lips otherwise you can use lip gloss instead of Vaseline.
And finally I think it’s not worth unless you have pink lips.