Change css colors in Quick Search block

I would like to change colors in Quick Search block. In forms_adv.css on line 51 I change color to different (darker) so I need titles in Quick Search lighter. When I change color in default.css on line 301 to #ffffff I have more inscriptions in white and I want to change the color of white subtitles only marked below with a red arrow. How can I do this?

In the same CSS section where you changed the background color.

.form_advanced_table th.block_header {
  background-color: #ECECEC;
  font-weight: normal;
  text-align: left;
}

Thats the CSS for the header. Notice there is no color for the forground specified. If none is specified it will inherit it's value. So to override the inherited value, just specify a color. Add a color line like so.

.form_advanced_table th.block_header {
  background-color: #ECECEC;
  font-weight: normal;
  text-align: left;
  color: #FFFFFF;
}

Thanks deano92964 ! It helped :)