Problem when using colored text in example 12(chat window)

I am trying to make a good chat window and encountered a problem about chrome text:

when using inputed many character, text will be wrapped so that it can fit the max width. however, if the first line which contain the color info such as [FF00FF] is scrolled up, the rest character will become default color. It works well at frist

After you imput or scrolled a single line

So, is there any solution?