I think MegaMente may actually have been asking for a system that dynamically changes the colour of text as the user types things in at runtime, rather than just hardcoding BBCode in the editor.
You could try doing something like this to process the user's text before it goes to the output text box:
- Make a variable (userText)
- put user's input in userText (from whatever you are using to capture it)
- set userText to: replace(userText,"banana","[color=#FFFF00]banana[/color]")
- set userText to: replace(userText,"apple","[color=#FF0000]apple[/color]")
- etc
- Set output textbox.text to userText
This means that if the user types in "I'd like a banana but not an apple", your game will convert that into "I'd like a [color=#FFFF00]banana[/color] but not an [color=#FF0000]apple[/color]" before it shows it on the screen.
Note that you might have to do a bit of work to cover word variants (eg. capitalised versions, plurals).