He doesn't have blond hair. Its more light brown. Just looks blond. Hate the manga, but I look at the new chapters just to see what the characters from the LN look like, like Alice and Delia.
in the manga its light brown. Its the same with movies that are based on movies: Hate for Eragon;Hate for medicus;Hate for LotR; Hate for HP etc. It is your imagination and when u see how other people imagine characters u get confused. Try playing Tabletop RPGs The Dark eye or DnD++ And u will have the same problem.
That manga is a sacrilege to the novel and if the author allowed such a thing he should lower his head and kowtow to his fans in shame.
If movie, manga, anime, and novel have the same very details about everything, what is use of adapting them to other media? Sure, I've not read CD manhwa, but I've read other manhwa, ex: Douluo Dalu, BTTH, TDG, etc. And they are not bad. If you like the novel, don't complain about the manhwa, because not everyone like to read novel, no matter how good it is. For this CD manhwa, you can try to read it, and judge base on your opinion.
About Doulou dalu and BTTH manhwa, I can still read them without problem and even tho there is difference between the novel like Sausage chant becoming a Tofu in Doulou Dalu(lol) . its still acceptable. TDG don't change that much, its just pretty awkward with naruto like setting tho. BUT CD IS A BIG NO!. it have a new scene that's not in the novel and it was shitty.
by minor change to the adaptation is okay tough, but CD manhua make some changes that drastically different from the novel also the manhua remove some stories in exchange for a gags. it's just like avatar the last airbender with it's awful live action movie adaptation IMO. like the poster above said, if you already read the novel read it with really low expectation or just pretend that the manhua is alternate story of CD if you don't want to be disappointed.