This recipe for ginger-garlic paste roasts the salt before putting it in the paste. Now, I never thought I've seen someone roasting salt before. What is the point of this? How does it change the flavor or properties of the salt?
The recipe calls for heating a "pan" on medium heat. Without knowing what type of pan this is, there is no way of knowing what reaction is going on there. Let me venture a guess, though.
I guess the pan is cast or mineral, seasoned, iron. The salt will react with some of the compounds from the bottom of the pan, making it "change its color".
Other types of pans will, most likely, do nothing. Non-stick, steel, aluminum don't react with salt.
As to the function of browning the salt, I can only guess that the flavor changes slightly from whatever you sautéed in the pan. You could pick up fish or meat or vegetable flavors.
As a side note, salt is used to clean cast or mineral iron skillets.
Salt in Asia is almost all sea salt, which can contain many things in addition to NaCl, up to 10% by weight according to processing method (or at least Wikipedia's page on sea salt says so). Korean roasted salt is roasted at temperatures of up to 800 C and is claimed to be less bitter, so I guess that at least some of the non-NaCl compounds are (a) volatile at high temperatures and (b) bitter-tasting. I can't access the original recipe linked by the OP, but I'm guessing that the roasting is a step in traditional Chinese recipes that isn't necessary for cooks using modern factory-processed iodized salt.