I think I just broke the page :D

I'm not sure what happened but I was trying to reset the colour of background to clear and now it doesn't let me neither to edit the "background" or to the real page. The error code it says on the page is: Warning: mysql_set_charset(): Error executing query in /srv/disk7/1860695/www/rahelotsa.ee/wp-includes/wp-db.php on line 723 Warning: Cannot modify header information - headers already sent by (output started at /srv/disk7/1860695/www/rahelotsa.ee/wp-includes/wp-db.php:723) in /srv/disk7/1860695/www/rahelotsa.ee/wp-includes/pluggable.php on line 1178 Thanks in advance!