Colored Tabpanels or Tabcontainer

Try by adding

CssClass="ajax__tab_xp"

And modify below style sheet and add it to your page to your page. This could possibly overwrite the default values.

/* xp theme */
.ajax__tab_xp .ajax__tab_header {font-family:verdana,tahoma,helvetica;font-size:11px;background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-vjV-PAQKyJH6-w_Kqv0BTA2&t=633059379620000000) repeat-x bottom;}
.ajax__tab_xp .ajax__tab_outer {padding-right:4px;background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-jzWbJi2Kb455_US1lKbtQw2&t=633059379620000000) no-repeat right;height:21px;}
.ajax__tab_xp .ajax__tab_inner {padding-left:3px;background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-hrEa2yrGgAaFvWHy-V4J8Q2&t=633059379620000000) no-repeat;}
.ajax__tab_xp .ajax__tab_tab {height:13px;padding:4px;margin:0;background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pJG1_o_Uc-Z3qxAIBY0LuVhvaewgoqFK9I3-vYe9Uavmw2&t=633059379620000000) repeat-x;}
.ajax__tab_xp .ajax__tab_hover .ajax__tab_outer {background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-j68wsU531jTH9EVG8sYTOg2&t=633059379620000000) no-repeat right;}
.ajax__tab_xp .ajax__tab_hover .ajax__tab_inner {background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-7jq3ZoVRZ7WCxIYHcXwYrg2&t=633059379620000000) no-repeat;}
.ajax__tab_xp .ajax__tab_hover .ajax__tab_tab {background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-ZYVFnHx6kXUXG04Ynnla_w2&t=633059379620000000) repeat-x;}
.ajax__tab_xp .ajax__tab_active .ajax__tab_outer {background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-ktJ4E_Nb8sRAhpxMCLTnkrf-oWI1IVNnfaxPZD5WHV41&t=633059379620000000) no-repeat right;}
.ajax__tab_xp .ajax__tab_active .ajax__tab_inner {background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-810LR9bochkP-d7OGb4OeA2&t=633059379620000000) no-repeat;}
.ajax__tab_xp .ajax__tab_active .ajax__tab_tab {background:url(WebResource.axd?d=6cVPmjA-1qKkVdAMBgxktzUXmqg-cXVoDQXFbVLF3pIWwicK7zkimKt0jbY1aBf-0d1buPTXJUdH40n2B0_rGA2&t=633059379620000000) repeat-x;}
.ajax__tab_xp .ajax__tab_body {font-family:verdana,tahoma,helvetica;font-size:10pt;border:1px solid #999999;border-top:0;padding:8px;background-color:#ffffff;}

Can we change the position of the tabs , say I want tabs to be right aligned