To be honest, I was quite disappointed with Apple's take on what is "Rose Gold". Rather than having the generally accepted "copper" color, they really went for rose (pink) gold -.-

The only issue I have with Space Grey is that the smallest dent/chip will appear to be very obvious. Ticks me off.

My wife's white/gold combination looks a bit eccentric. White/Silver however has that classic look. The white facet will be fine, you just need to find the right wall paper to make it look great. Anything with a white/bright background will make your iPhone pop. For instance, that Purple Chrysanthemum on a white background featured on iPhone 6. It won't be a feast to the eye though when the screen is sleeping.

Not just white. Whatever colors, after a significant period of time, will be boring. Apple/3rd party companies know this and that's why they came out with a variety of phone cover colors.

Some people love that uniformity in color, It's like a clean slate, almost mirror like piece of brilliant technology. It gives out a sleek and elegant vibe to the user but the user has to make sure that the surface is always finger print or stain free.

The gold looks tempting at first look which prompted my wife to select it. She was using a clear casing for the first 6 months and then just switched to a color opaque casing but then again, different people different perception. You may actually love how it looks more than you know it =)

iPhone 5c attempted that and I don't think it is a very good move. Sure, it's fun to look at but can you imagine if people are bored with classic colors such as Black, White and Gold in just a few months, seasonal colors would wear off faster than you can blink. Then again, you always have the option of colorful casings for that.

I think Apple has already done a very bold move by releasing a Pink (Rose Gold) iPhone but as you can see, even that, it is a very subtle color. the iPhone is not meant to be fun per se. there's always a perception that iPhones are very corporate based. I cannot imagine Warren Buffett carrying a green iPhone XD

However, having that option of choice is a nice touch but will significantly increases the production workload for least popular colors and may even pump up the operating costs.

Besides, it's always Apple's style to choose for the user.

Most phones heat up during charging. the iPhone is no exception so yes, it's normal for the iPhone to heat up when it's in charge and during long usage.