It's rather straight forward to make rings that look like these; making them actually light up is a different story; doing it inexpensively is probably out of the question. But... with enough money and time it's probably doable. Don't expect them to be able to make you fly though.
I think even the comic book colors are bit off. Blue is more of an aquamarine. Indigo is too much blue and not enough red (you're right about this). Violet (or whatever Star Saphire is supposed to be) is more of a pink. I don't know if these were artistic choices or technical issues with printing, but I basically tried to mimic what they did.
On a separate note... I think it's unfortunate that they locked in on seven entities/colors, because there are way more emotions and an infinite number of color variances to explore. They could have had some interesting stories about other emotions like despair, joy or lust, just to name a few.
Yes, actually I do think that the seven "rainbow" colors work the best for simplicity and the mere fact that they're probably the only seven color most non-artsy type people can actually name. I still think the idea is a bit goofy: that emotions control the DC universe/multiverse. It's a little new-agey for me, but it is creative... and just to contradict myself, I think it would be even more creative, though too confusing, to open the storylines to a whole range of other emotions.
Also, didn't anyone ever point out that will power isn't really an emotion? Neither are life or death, but I'm assuming that black and white aren't really part of the spectrum as DC sees it. They're something different and beyond that.