Unbound

[Timbow]

... I'd like to change the name text of page (presented on top of the front picture) from black color to yellow. ...

The file style.css : Backup then open it in a text editor (or in the GS Theme Editor) Around line 275 you will find

Code:

#header-wrap h1#logo-text a {
    position: absolute;
    margin: 0; padding: 0;
    font: normal 62px Georgia, 'Times New Roman', Times, serif;
    letter-spacing: -1.5px;
    color: #070000;
    text-decoration: none;
        
    /* change the values of top and left to adjust the position of the logo*/
    top: 135px; left: 48px;    
}

Change the colour declaration to
color:yellow;

Below it you will find the selector
#header-wrap p#intro
followed by the declarations for the small tag-line text under the logo text - you might want to change the colour there too. HTH