Should i be worried if my mitsubushi l300 has an amber oil lamp on the dash board but the oil is full ?

Go to Autozone have them pull the codes off of your vehicle then get the issues fixed.

Orange is a warning light, it needs checking as to why it is on

Oil lights usually measure oil pressure not level. If the motor sounds and runs Ok you probably have a faulty sensor. Try replacing it and see what happens.

Is it just an oil change reminder?

Of course you should be worried. Warning lights come on for a reason, you need to find what that reason is. The longer you ignore it the more expensive it becomes.

You need to find out WHY the oil lamp is lit... READ the owner's manual that came with the car. It will explain the meaning for various warning lights.

Oil lights are red!

Check the coolant level in the radiator, not just the reservoir tank.

Find out which warning light you're looking at.

If the engine is running and the light stays on, shut off the engine immediately. Change the oil and oil filter and run the engine again. Light does not go off, it is time to get the car towed to a mechanic.

Yes. If a warning light is on, it's on for a reason. It could be that it's overfilled, or that it's due an oil change,

No if you check it the light goes away next time buy anything else than a Mitsubishi .Mitsubishi lol 🍆