Racism in China is a big problem, but the laundry advert alone isn't certainty not a big issue and is pretty over blown: being overly political correct around lighthearted comedy.
The skin pigment 'melanin' is what causes a black person's skin to be black, and is also the same as in a non-black person's tanned skin. It's a added pigment that the absence of causes light skin. Removal of melanin can happen (through non-laundry!) causes such as developing vitiligo, or being born with albinism (a genetic condition which exists in all ethnicities not just black people). Removal of melanin literally turns a darker skinned/haired person white (but obviously not changing other features).
The American TV show Everybody Hates Chris, based on comedian Chris Rock's childhood experiences made almost THE EXACT SAME JOKE more than once [1] [2], making fun of the very strict African-American mother trope of threatening a misbehaving child with 'slapping the black out of you'.
The laundry commercial may have some problematic connections with the ideas of 'clean' and 'attractive'.
America has a long history of minority TV shows aimed at mass audiences tackling stereotypes, Everybody Loves Raymond for Italian-Americans, Fresh Off the Boat for Asian-Americans, and a huge number of African-American cast shows including The Jeffersons, The Cosby Show, Fresh Prince of Belair etc. Comedy shows with characters with minority experiences are a good way to improve understanding. It will be unfortunate if lighthearted comedy dies because excessive political correctness.
[1] https://www.youtube.com/watch?v=44mTfEcP76o
[2] https://www.youtube.com/watch?v=UPmqVW_qLmk