This may well be implemented in the final version of the game. They mentioned something about this in a video somewhere but were not far enough along with it at that moment.
Must of missed this part of them discussing it. Am aware rides will have some of the colour adjustment but didn't hear anything otherwise about texture/colour options. Must of been just as beer was brought to me. Will have another watch later anyways to check through it all in detail.
It wasn't the live stream, at least not this one. I'm sure it was just a passing comment about customizing rides and shops etc. And whether to use colour swatches to pick colours. But it was very vague, and I don't get the impression it was anything they had worked on yet. If I can remember where it was I saw it, I'll post a link, but I've seen so many on youtube that I doubt I will find it.