Never going to happen. Genes are more binary than that, with recessives and dominants.
For example, from time to time you can read that blue eyes are “going extinct” or “disappearing”. Nonsense. They are becoming less common but the recessive genes for that phenotype still exist and will continue to exist. We’ll continue to get blue eyed/green eyed/hazel eyed babies being born, often to two brown eyed parents. While some traits are controlled by multiple genes and can look more intermediate - such as skin and hair color - all the variations will still exist. Often in novel combinations. We will continue to have people of unusual skin color, whether dark or light. We’ll continue to have hair of all colors and textures, even if some (like red) become less common as the population becomes more (but never entirely) heterozygous.
Yes, there will be a median range that will be darker than what is considered typical European and lighter than what is considered typical African, but even there we’ll have a range of traits.
Ditto for height and “shape”. We’ll have a lot of people within a typical range but we’ll continue to have unusually tall and short people due to genes (as opposed to pathological reasons such as medical dwarfism or pituitary gigantism). We’ll continue to have people unusually “stocky” or unusually “lean”.
People are not going to become a species of universally homogeneous appearance.
Consider wolves - there’s a “typical” color range, but wolves outside of that - unusually dark or light - certainly exist as well.