I did have a write up on how to do this for 6.1. Never did one for 7.0. The process is similar and easier then D6.
first in templates/base/ make a copy of designbox_1.html and name it designbox_4.html
Edit designbox_4.html and rename the css class names so they look like this.
<div class="disignBoxFirst4">
<div class="boxFirstHeader4"><div class="dbTitle4">__title__</div>__caption_item__</div>
<div class="boxContent4">__designbox_content__</div>
__bottom_item__
</div>
save the file and upload to your server.
That creates a new design box to use. Now you need to add css for it so you can change its colors.
now edit templates/base/css/general.css and add this to the bottom.
.disignBoxFirst4 {
position:relative;
border:1px solid #0D3966;
margin-bottom:10px;
background-image:url('../images/head_cutting.gif');
background-repeat:repeat-x;
background-color:#000000;
}
.boxFirstHeader4 {
height:17px;
padding:3px 0px 0px 8px;
font-size:12px;
font-weight:bold;
color:#FFF;
text-align:left;
border-bottom: 1px solid #0D3966;
}
.boxFirstHeader4 a, .boxFirstHeader4 a:link, .boxFirstHeader4 a:active, .boxFirstHeader4 a:visited {
text-decoration: none;
color: #FFF;
}
.boxFirstHeader4 a:hover {
text-decoration: underline;
color: #FFF;
}
.boxContent4 {
overflow:hidden;
font-size:13px;
padding:10px;
}
.disignBoxFirst4 .boxFirstHeader4 .dbTitle4 {
position: relative;
float: left;
}
Now all you need to do is edit the database table sys_page_compose, find the page block you want to change and change the designbox field from 1 to 3
Now you need to clear the cache, or remove the file sys_page_compose.inc from the cache directory so dolphin rebuilds the page cache.
I don't know where you saw this bx_profile_custom_units table info, but it has nothing to do with it, so don't touch it. I believe that table stores info for members profile customization. It has nothing to do with site design boxes.