Raditz's arrival on Earth actually began Dragon Ball Z with the Saiyan saga. The death of Goku's brother actually convinced Napa and Vegeta to join their now-deceased companion, but the Saiyajin prince appeared with a very different appearance than we know him today.
In Vegeta's first appearance in the anime, the legendary prince appears with the red hair and green and orange armor, a decidedly different aspect than what it looks like when it arrives on earth. Today there is a variant of Vegeta with red hair thanks to the Super Saiyan god, but it was one at the time Error caused by TOEI Animation and Akira Toriyama.
In fact, it is not a filter as many mistakenly believe, but a Misunderstandings between the sensei and the animation studio. In fact, Toriyama does not appear to have sent the characters' color sketches to TOEI Animation, as the writers usually have to do in order not to cause chromatic aberrations, and for this reason the studio interpreted the mangaka's character designs in its own way. Of course, the sensei realized the mistake too late and did not hesitate to contact the studio to warn him of the sensational mistake, which was only corrected in the following episodes.
If Broly doesn't have black hair, as theoretically all purebred Saiyans should have, it's because the device Paragus uses to control the mighty Saiyan doesn't completely keep the character's deadly power in check. On the other hand, did you know this anecdote? Let us know with a comment below.