Some improvement for Text Coloring Panel usability

And add Hex-to-Unicode translator for getting cool Unicode character (Hex-To-Unicode translator enable user to get the Unicode character listed as Hexadecimal code from websites).

More commit message in https://github.com/xponen/Zero-K-Infrastructure/commit/b524d2236f2d5b603d7ebb5c5ca10d89b78ad5f3