Well you could do it if your familiar with editing CSS. To change the site title color go to:
#site-title a{
color: #ffde01;
To change the site tagline color go to:
#site-description{
color: #ccc;
font: 12px/18px ChunkFiveWeb, Georgia, serif;
padding: 2px 40px 15px;
text-transform: uppercase;
}
Basically search for the yellow color font color: #ffde01; and you could test out some changes. I suggest doing this on a local PC test site before attempting it on the real thing though.
Your header image is located at http://www.<your-domain>.xxx/wp-content/themes/fanwood/images/bg-header.png if you have installed it in the root. The dimension of the image is 920×216.
Simple make the new header and replace this file with the image you want with the same file name.