What difference would skin color make from a physics perspective?
Would there be any difference in the energy emitted, reflected or absorbed?
Would it affect what is emitted, reflected or absorbed?
the darker the color the more absorption of sunlight , and since the process is reversible there will be more emission for darker colors.
In skin, the dark color denotes a lot of melanin, and melanin is the defense of the body against ultraviolet radiation from the sun. It does not allow it to penetrate and destroy the lower layers. The first evidence of damage is sunburn.
Can physics provide an analysis of why paler skin is more prone to melanoma?
This is a biophysics question. I believe it is due to the lack of melanin which allows penetration of ultraviolet and mutation of lower level cells that can turn cancerous.
Does melanin in an of itself have any physics applications? Is is used in physics experiments, etc.?
Not that I know of. The use of dark colors when one wants to absorb sun energy (( as in sun water heaters) and light when one wants a lot of reflection (as on rooftops) is of course general.