Cathy, I've seen these same recipes and kept them in the back of my head last night while at Ron of Japan. In eating my shrimp dish last night, I tried several bites of just the yolk sauce. By itself, it's somewhat bland. But when tasted with the shrimp, which has been essentially sauteed in a little oil, a little butter and some sake (and then I dip it in a little soy sauce), it is a combination that has a tremendous flavor. Also, the cooking/steaming of the yolk/oil mixture yields an interesting and very light texture.
Thus, the additions of food coloring, sugar, rice vinegar, soy sauce, paprika, garlic powder, etc. etc. that one finds in all of these online recipes -- I don't think that's how Ron of Japan does it. Others might do it that way, but I don't know (as I mention above, it's been so long since I've visited any other spot serving a similar dish). But I think a simple combination of oil and yolk, and then cooking the shrimp in a style similar to that used by Ron of Japan, will do the trick. That's not to say that the recipes found online cannot yield delicious versions of the shrimp and sauce.
All in all, I don't think it's that difficult of a dish to recreate. The most difficult part I found when I first tried it was getting the right proportion of oil to yolk, and I'm not so sure that I didn't use the right proportion . . . I didn't cover the pan (unlike Ron of Japan) and that might be the reason I think the proportions seemed off. At Ron of Japan, the cook seemed to first desire a very quick sear for caramelization, and then sake and a cover on top of the shrimp for steam, probably to ensure the right consistency of the yolk mixture atop the shrimp. I will note that when they scoop this yolk/oil mixture on top of the shrimp, it looks like mayonnaise, albeit much more yellow.
Now if someone can only tell me how to duplicate a Pizano's/Malnati's or Burt's crust . . . I've tried so many times without success. I believe it's all in the butter and the proper way to incorporate the butter . . . I just have not yet figured it out.