
-----
Just if anyone happens to have the same problem:
by using pdfborder={0 0 0} instead of colorlinks=true and the color definitions, the boxes vanish as well and the text stays pitch black.
happy easter!
Learn LaTeX easily with newest books:
The LaTeX Beginner's Guide: 2nd edition and perfect for students writing a thesis
The LaTeX Cookbook: 2nd edition full of practical examples for mathematics, physics, chemistry, and more
LaTeX Graphics with TikZ: the first book about TikZ for perfect drawings in your LaTeX thesis