They're for it because the area is boring and uniform. There is nothing wrong with color, especially if it's in an entertainment district. I mean, there is nothing great architecturally about the Gateway. It's already a faux-cityscape that looks like something out of Disneyland anyway - so, why not at least brighten it up a bit? Sure, you could totally overhaul it and create an entirely new facade, but that's not done on the cheap.
But the current look is stale, drab and boring. Even the addition of more earth tones won't change this, especially since Salt Lake has enough of that anyway.
If the Gateway is going to survive, it has to becoming gimmicky and unique. I have no problem with lighter pastel colors. A lot of cities outside the United States utilize this color scheme in their developments (if not darker, more colorful than what I'm proposing). If done right, it looks absolutely colorful and inviting:
That is one thing I've never liked about the development in the United States - it's very conservative outside some beach area pockets. We overdo the earth tones and that's really what dominates the Gateway, as the beige is the bedrock of so many earth tone color schemes - with maybe a forest green, sand brown and a hard red thrown in for good measure.
Shake things up! Let's create something that pops and makes people think, "wow, I want to check that out..."