If we can tan, why is it impossible for us to change our genetic skin colour?

#1

Both our genetic skin colour and tanning are related to melanin, so why is it
impossible for us to change our skin colour in the same way we get a tan?

#2

Genetic skin colour is something we are born with and we have no power to alter it.
Genetically, skn colour is the result of both biological parents genetic makeup.
The tyrosunas enzyme is resonsible of our skin, eyes and hair colours.
Meanwhile, tan is the result of skin damage from the sun.
However, if you get a deeper tan, it may take years to completely get back to your
natural skin tone.