Unable to write anything in the username text-box!

I recently found out you could write down coloured-text in-game so I decided to use the coloured-text as my username. (In order to perform this action you hold down & then a button pops up then you press any number then write down the words you wanted to write) So I changed the colour and I wrote down my username and I was expecting it to be in colour but when I typed my first letter in I couldn't type anything down in the text-box. So my username is an empty space.