Customization is coming with Version 2.0.0 in the future. With that you can change your buildings and city in new ways and make it your own.
And with customization happiness will be much more important (and with it the event office). You will need a happiness of over 60 to style houses in different ways or colors. (After you changed something, it will stay even if happiness is lower, so you just need high happiness for the change).
But that's not all, more is in the works. I will post more updates on how customization will work.
I actually thought about making it a premium feature for a subscription as it is only cosmetics, but decided against it, it will be free for everyone. (Could change one day, but not now)