Hi,
for site title maybe you need to consider to set header logo. If you want to change your site title to another color,
open your style.css file and on line 778 you have this code:
#main_logo_textual{
font-size: 24px;
line-height: 24px;
margin: 0;
color: #737d82;
}
Just change color: #737d82;
to #ffffff (white).
Below that code you have this:
#main_logo_tagline{
font-size: 12px;
margin: 0;
color: #737d82;
width: 220px;
line-height: 17px;
}
Also change color: #737d82;
to white. This is for subtitle on your site.
To set menu items to white, in style.css on line 870 you have this:
nav > ul > li a{
color: #6d6d6d;
font-family: 'Raleway', sans-serif;
font-weight: 700;
font-size: 14px;
text-transform: uppercase;
text-align: center;
display: inline-block;
padding-right: 33px;
padding-left: 33px;
}
Change color: #6d6d6d;
to color you like.
Maybe you will need to clear your cache to this changes works.
Kind regards