Most of the people on this forum have spent countless hours researching ingredients and formulation. They have taken what they've "learned" and applied it to formulating for specific results and then experimented. Tested their formulation, tweaked, tested, tweaked, tested ... repeatedly until they have what they were attempting to create.
You will find some basic formulas here, but they will not provide you with what you are attempting to attain. For that you will need to do your research here and elsewhere to find the ingredients necessary to create the formula you're wanting.
Step 1 - Research how to create a simple lip balm.
Step 2 - Find an ingredient that is food safe and will reduce pigmentation. What is the ingredient? Can it be incorporated into a lip balm formula. Is the ingredient a butter, oil, water based, powder? Are you able to find a supplier for the ingredient?
These are just the beginning steps. You will need to spend some time "learning" about ingredients and formulation.