New Create New World UI doesn't support text formatting codes

When typing a text in the world name box, or showing the formatted text description in the resource pack menu, the custom color won't appear since the formatting isn't supported in the new UI.

How to Reproduce
1. Enable the new UI in the Create New World screen.
2. Go type "§b" or "§5" and the name of your choice to test if the color shows up in the world name box.

Expected Result
The color shows up in the world title box in the new UI.

Observed Result
No color changes, just text.