Miami is no more unique than any other city is when it comes down to it.
I don't have a problem with different colored tiling along concourses, because frankly that really isn't that revolutionary of an idea. I'm more critiquing Loria's general treatment of the park foremost as an aesthetic object rather than a theater of baseball. Going as far as to restrict sponsoring contracts purely on account of aesthetics is not a policy I agree with.
And your illustrations from Sun Life aren't particularly telling. They seem obnoxious simply because the team is so desperate for revenue that they are forced to pack as many ads per square inch on the teal tower area as much as possible. It's not really the color that is the problem, it's just the multitude of the different shapes and designs packed closely together. The best way to avoid this would be to simply allow less ad space. That's why the older picture of Joe Robbie seems more aesthetically pleasing.
In the end, I don't see how looking at a giant wall of yellow advertisements will be any more desirable or easier on the eyes.
Going back to the original topic, it's not like the every single nook and cranny of the ballpark down the first baseline is going to be painted yellow (or red down the 3rd baseline / blue behind home plate / green in the outfield). Only the concourses, the walls that separate the "upper" tier from the "lower" tier in the lowest level of seating around the infield, and (as construction has progressed) certain box seat / handicapped areas will feature the different 4 different colors around the ballpark.
A few pictures of the concourses have already been posted, but the picture below shows how little of the colored tiles you'll actually see from the field:
The use of different colors' main purpose from what I understand is to help people know where they are within the ballpark (red = 3rd baseline, yellow = 1st baseline, blue = home plate, green = outfield).
What the article is not clear on is whether companies such as UPS or Home Depot like they mention will simply not be allowed or could they "adjust" their logos to fit within the color parameters (though this doesn't make sense for companies whose logos' colors have come to be instantly recognizable with that company. For example, the UPS logo uses a yellow/gold already - could UPS simply put just a yellow "UPS" up without the brown? I'm sure just plain white logos would work too.
Bottom line is - we'll have to wait and see.
As for new colors, I don't like the idea of departing from the teal (or whatever the current non-"teal" color is called), but will reserve judgment until the new uniforms are revealed. I just pray that orange or red will NOT be used in any capacity. There's already waaaay too many red teams and orange, well.....I just don't like it that much. I suppose as long as we don't get rainbow uniforms kinda like the old Devil Rays ones, I'm ok. Talk about teal being "outdated"......