It’s a suggestion/question that comes up a lot for sure. I’ve thought about maybe adding a FAQ that would include an official answer, maybe pinning it to the top of the navigation bar (next to Members, Wiki, Buy), or maybe adding it into the “welcome to TCF” private message that each new member gets. It’s on the thinking table, but I also worry about having too many things to read over that things are cluttered. Plus there will always be a percentage of people that never read anything first, they’ll just plow in with a thread about it even though it’s been addressed in a FAQ.
By the way, the most official answer is from 505 Games (the publisher of the console and mobile versions):
Question: Can we have mod or texture packs?
Console Answer (source)
Mods or Texture Packs are currently not supported on console platforms.
While it is something we would think would be great to see in Terraria on console, it’s currently not a feature we plan to introduce.
Mobile Answer (source)
Mods or Texture Packs are currently not supported on mobile platforms.
While it is something we would think would be great to see in Terraria on mobile, it’s currently not a feature we plan to introduce.