My experiences and research into Regal Angels indicated that they are basically a Yellow fish, as they grow, the white, blue and black line grow in. Baby Pacific, Indian Ocean or Red Sea Regal Angels all look the same as very young fish. As they develope, the white, back and blue lines grow in, displaced the yellow colors. We can see that the changes stop early with Indian Ocean and Red Sea fish while continue with Pacific Regal angels. Pacific regal have wider bands of white, blue and black resulting in narrower yellow area. Of course the chest area also darken to greyish blue.
I am at work, so I don't have access to the images of most of my Regal Angels, only those that I posted on line. Later today, when I get home I can post pictures that show the differences of adult Regal Angels between Pacific and Non Pacific area. I was never able to come up with any clear differences between Indian Ocean vs. Red Sea, other than maybe Red Sea is "more orange" which I don't think is true.
I would disagree that Pacific Regal are less vibrant. They are extremely beautiful also, but is a darker fish over all. Certainly more blue. One can say that Non-Pacific Regals have their color changes arrested earlier than that of the Pacific ones. I certainly don't think that this arrested development is a bad thing, even if we always have bad connotation to the word "arrested development". Non Pacific Regal Angels just looks different than the Pacific one. I like both essentially equal.
If anybody look at my Pacific Regal angel below and said that he is not a beautiful fish, I would say that (s)he is lying

(not really)