Well Gehn, I don’t see how my point is* provable*, it’s just an opinion about other people’s opinions after all. Especially when you use words like “vivid” since I really can’t know what makes something vivid for you. But if it’s examples you want I’ll give it a try…
http://www.panzerdragoon.net/screenshots/images/pds_girigiri_excavation_site_4_screenshot_03.jpg
http://www.panzerdragoon.net/screenshots/images/pdo_screenshot_57.jpg
From TWotA’s screenshot section, of course the Saga shots are from emulation so they may not accurately reflect your color association. But that brings up another point, I’ve heard people say they thought Saturn had a washed-out look compared to Playstation at the time, and on some TV’s it 's video output was especially subdued.
http://www.panzerdragoon.net/screenshots/images/pdo_screenshot_50.jpg
http://www.panzerdragoon.net/screenshots/images/pds_girigiri_arachnoth_screenshot_03.jpg
The series has always employed some pretty raucous color schemes in places, I think it’s because there’s so much more detail and things start to look semi-realistic in Orta that perhaps some people have trouble resolving the alienness of the vision with a sense of place and believablity? That’s actually one of the more impressive aspects of Orta for me, the balance of vibrancy and subtlety in most areas. On the other hand I think it could have been better served with a more impressionistic approach to the backgrounds, less actual detail and more filtering and shader trickery.
http://www.panzerdragoon.net/screenshots/images/pd_pc_screenshot_04.jpg
http://www.panzerdragoon.net/screenshots/images/pdo_screenshot_52.jpg
And speaking of impressionism, I really think that’s what the Saturn games had going for them most of all, everything was reduced to the most basic necessities of communication, primary form and color. It left more room for the player to fill in the details with their own imagination and see what they wanted it to be. But what really set the games apart after that was the subtle and organic animation, something Orta retains in full.
I really can’t relate to complaints about the dragon designs at all, it is of course purely preference anyway. I don’t see how anyone thinks Orta’s designs are anymore different than any of the other games are from each other. Base Wing has more obvious similarity to the Blue Dragon and the starting form of Saga than they do to any of the Zwei forms. It’s got claws just like concept art for the Blue Dragon… the Saga dragon has hooves actually. But all 4 games have an equally unique style in that respect.
In fact it seems to me that Saga’s dragons are the most alien to the whole series. Heavy Wing is definitely one of the strangest in later forms, but Glide Wing has much in common with other pure-type designs throughout the series and some features that are very reminiscent of Atolm. I have a memory of someone taking exception to the claws on the wings of Base Wing and even that has precedent in some of the Saga forms, I don’t have any images of the forms though.
Ahh well, I know you hate long posts Gehn but you did “dare” me so you don’t get to complain about it… 
I obviously have my own nitpicks about Orta but it in no way breaks the series as a game or as art to me. And it’s still my pick for the most impressive and beautiful game on XBOX, which is saying something.