Colour of Magic was pretty bad. Just like writing-wise, he he hadn't found his feet yet.
He also hadn't found the line to tread between satiring people and humanity in general, and taking cheap pot-shots at real people...I was a big fan of Anne McCaffrey when I first read Colour of Magic, so him making fun of Lessa and Dragonflight in the book landed poorly on me.
Like, looking back, he was a nobody at the time when that book was published and McCaffrey was Someone, and it probably felt like he was punching upwards at Anne McCaffrey who was a pretty big name in science fiction--but as his own fame/status as a writer grew to equal/surpass hers, it just looks like he's ripping on a fellow author for no good reason. Obviously he did that to Conan too, but the author that created Conan was long dead and not living.
And I think he figured out satiring living authors in the same field as he was a pretty shitty thing to do, because he eventually stopped doing books that had a chance of ripping real living people down.