There are no specific or detailed physical descriptions of Daisy or Gatsby. For whatever reasons, Fitzgerald chose not to create literary portraits of either, choosing instead to make passing references to their general appearance. When the novel was published, critics noted the lack of physical details in developing Gatsby's character, and many considered it to be a flaw in the narrative. It is interesting that Tom, Myrtle, and George are all described in far greater detail, as is Catherine, Myrtle's sister.
Daisy is described in Chapter I as being dressed in white, her face "sad and lovely with bright things in it, bright eyes, and a bright passionate mouth." Fitzgerald describes her voice in more detail than he expends on her physical attributes.
According to Nick in Chapter III, Gatsby is "an elegant young rough-neck, a year or two over thirty." The nature of his smile is observed, along with his speech patterns, but the features of his face are left to the reader's imagination.
Why Fitzgerald chose not to create indelible images of Daisy and Gatsby can only be surmised. Surely, it was not for lack of literary talent or vision. Perhaps by leaving them non-specific in physical appearance, Fitzgerald directed the reader instead to the behaviors and mannerisms that defined each of them so clearly.
The simple answer to your question is "no." There isn't one accurate description anywhere in the novel. Let me tell you, I tossed and turned over your question. This is my very favorite book to teach, and I was floored that I was stumped by this. You see, for me, Daisy will always be Mia Farrow and Gatsby will always be Robert Redford. I suppose my mind clung to the visage from the movie because of the purposeful lack of description in Fitzgerald's novel of genius. But I digress . . .
Let's focus on what is said about the two characters. Then perhaps we can approach that analytical one for both that you need so desperately. In regards to Daisy, I think Fitzgerald does a good job with his original physical description:
Her face was sad and lovely with bright things in it, bright eyes and a bright passionate mouth, but there was an excitement in her voice that men who had cared for her found difficult to forget: . . . a promise that she had done gay, exciting things just a while since and that there were gay, exciting things hovering in the next hour. (9)
Further, there are numerous times in the book where Daisy's face is described as "white." One example is the flowing and billowing white curtains surrounding Daisy as Nick first sees her. Another is the flashback where Daisy and Gatsby first kiss. Here is yet another example where white is used in regards to Daisy:
Sometimes she and Miss Baker talked at once, unobtrusively and with a bantering inconsequence that was never quite chatter, that was as cool as their white dresses and their impersonal eyes in the absence of all desire. (12)
Gatsby, of course, is another story. In regards to the purely physical, I would suggest a few short sentences in Chapter 3 when Nick finally meets Gatsby (and right after he uses his very prominent "Old Sport" phrase to describe Nick as well as anyone else):
He smiled understandingly--much more understandingly. . . . Precisely at that point it vanished--and I was looking at an elegant young roughneck, a year or two over thirty, whose elaborate formality of speech just missed being absurd. Some time before he introduced himself I'd got a strong impression that he was picking his words with care. (48)
In my opinion, the best description of Gatsby is a few pages into Chapter 4:
This quality [balancing himself on the dash board of his car with resourcefulness of movement] was continually breaking through his punctilious manner in the shape of restlessness. He was never quite still; there was always a tapping foot somewhere oar the impatient opening and closing of a hand. (64)
In regards to Gatsby's words or, even better, how Gatsby speaks, there is light on the very next page:
He looked at me sideways--and I knew why Jordan Baker had believed he was lying. He hurried the phrase "educated at Oxford," or swallowed it, or choked on it, as though it had bothered him before. (65)
In regards to every single example quoted here, I keep asking myself, "Is this even a physical description?" You see, this is the beauty of Fitzgerald's genius: to add one small idea, one small step at a time so that our image of these characters is continually shaped by the formless wealth around them. Furthermore, the longer I think on this subject the more I think that Fitzgerald has us playing right into the palm of his hand, . . . ironically Fitzgerald spent his life playing right into the palm of Zelda.
No there isn't! You can simply infer what both Daisy and Gatsby look like.
You will need to do some inferencing. Look at Daisy's first description: she is described as being light as air, floating upon the lounger she sits on. Focus on her mannerisms, her voice, which Nick finds hard to identify and can only provide examples of (like describing it like a tonic). Then pay attention to how Daisy changes. As the book progresses, she sits heavy like lead. Look in chapter 5 and 6 at the early descriptions of both Gatsby and Daisy as young lovers. It will give you a better idea of what they actually looked like, but for an analysis, don't miss how they carry themselves. Nick offers lots of details on how Gatsby dresses, stands, and speaks. This has a lot to do with the image Gatsby is trying to project and the person he is trying to be. Good luck.