Thank you for your readiness to help. But I decided this is too far beyond my capabilities and asked a geek friend for help. I try to avoid asking him too often because it usually turns out I owe him a beer, or a crate of beer and I might easily go bankrupt in the process.
Now the code of my template contains a lot of 'style' and 'class' (it used to be just html) and my links are in the desired colours.
By the way, does anybody know a
very simple way of securing one sub-page with a password?