theme classic colour change

I realy tryed but now I have to bother you sorry- I cant find the place to chance the text colour of my gallery - http://aggerfoto.de/agger/index.php?option=com_gallery2&Itemid=31- as you see the text in the header is just fading into the background ....
I did try the tip frtom dave with the firefox browser and the web development tool but I´m just too stupid can anyone help? Thanks a lot I promise to work on it ;)