I find that those types of exercises are fun to fill out after I've already written the novel or are far in the process of it. They're more for my amusement, but if you find that you know the answers already, chances are that your characters have become their own people during the course of the novel. While it's not necessary to know their favorite color, if they've shown a preference for green or purple or whatever in the novel, you can figure it out. And it's much better than saying, "John chose a red shirt, his favorite color." Because, who really needs to know their favorite colors?
If you can fill out the exercises & come up w/ a well-developed character from that, rather than just mechanically presenting what you've made up for them, that's great, but you probably won't need more than one of those. If I were looking for one that would help me create a character, I'd look for one that focused on things more like what drives them, what activities they take part in (the fact that one of my characters takes gymnastics has become important when she's fighting later in my novel), their dreams, their fears, things that may have influenced them in the past, specific things about their personality. With rare exceptions, knowing their birthday or their favorite color won't make a difference, but knowing their background & what drives them will help you understand them.
And then when you write, if you realize that something doesn't work for a character, feel free to change it. Those exercises are not meant to be set in stone.