Joined a new company few days back and found out that colleague with very less experience than mine is at a very higher salary..
How to politely convey ur boss to match the salary..

Shrug, how did you find out? Not sure you're even supposed to know, might get you pay but might bring bad karma.

Before this, did you think your pay was low? And is the other person doing the same job as you?

@CodeBane
I found it out accidently..
No, before that I thought my salary was ok but I am practically doing more than double his work..

Are you under a contract? If so what does it state about renegotiation?

If you don't need to wait for your contract to be renewed ask politely for a salary renegotiation.

Besides straight up telling your boss that you deserve a raise, you can back your argument up with things like:

#1 Official salary stats. Look at Stack Overflow's salary calculator and other sources. The implication is that you'd get that much money working somewhere else and they know it. Worked for my very first dev raise.

#2 You've spoken with other devs with similar jobs and they make more money than you do. These devs can be real or imaginary. I was lucky enough to have a get-together with friends from my University one week before my mandatory yearly salary chitchat so I was very aware of what I could be making. This became my argument for my second raise. The get-together was true, the numbers were based on what my friends thought I deserved. I took a chance and was pleasantly surprised when boss agreed. Thanks dudes, I owe you.

Just remember that you're doing a great job and that you deserve to be compensated for it.