Title name invisible

Hi there,

I am discovering wordpress, looks amazing. However I am encountering an issue with my website:

I am not able to change my webesite title color. It is set to white whith a white blackground and whatever I do to change it it stay the same.
It seems that there is another style that overwrite my seetings but I cant manage to find it.

Anyone here ever encountered that issue ? Some help would be really apreciated.

Thanks !

The page I need help with: [log in to see the link]