We don't have docs on how to do this at the moment.

Basically, you need to change the stylesheet.

I've also put logo's, changed starting messages by modifying Header.ascx, and (for Windows Authentication on our network) added a few instructional messages in Register.aspx.

Here are the Header.ascx changes (actually only insertions) I've made:
--------------
<%@ Control Language="c#" AutoEventWireup="false" Codebehind="Header.ascx.cs" Inherits="Gemini.Header" TargetSchema="http://schemas.microsoft.com/intellisense/ie5" enableViewState="True"%>
<LINK href="StyleSheet.css" type="text/css" rel="stylesheet">
<TABLE class="navlogobarborder" id="tblHeader" cellSpacing="0" cellPadding="0" width="100%"
    border="0">
<!-- yarko's additions -->
<!--  Just enable / add this for deploying on development server
    <TR>
    <H1 style="color: red">
    <center>
    THIS IS A TEST SITE
    </center>
    </h1>
    <h2 style="color: red">
    <center>
    FOR SERVER DEPLOYMENT:
    </center>
    </h2>
    <h3 style="color: red">
    <center>
    Do NOT Enter business data here!!!
    </center>
    </h3>
    </center>
    </TR>
    <TR class="navlogobar">
-->
        <td class="navlogobar" valign="center">
        </td>
        <TD class="navlogobar" align="left"><a href="http://my.company.com" target="new"><IMG alt="MyCompany Division and Group" src="http://my.company.com/standards/images/Logo.gif" align="top" border="0" runat="server">
            </a>
        </TD>
        <TD class="navlogobar" vAlign="center" align="center">
        <h3>My Division - MyCompany Test Site</h3>
        All content herein - <b>MyCompany Confidential Proprietary</b>
        </TD>
        <TD class="navlogobar" vAlign="top" align="center">
        <h5>MyDivision-Group Test Site</h5>
        <table cellSpacing="2" cellPadding="2" vAlign="center" align="right" border="4" frame="hsides" >
            <TD class="navlogobar" vAlign="center" align="left">
                <B><a href="FAQ.htm">&nbspFAQ&nbsp</a></B>
            </td>
        </table>

        </TD>
    </TR>
<!-- end yarko's additions -->
    <TR class="navlogobar">
        <!-- Product Version & Desc -->
.....
-----------------------

For Register.aspx, I simply found the fields where I wanted to add a line of instruction, and inserted the appropriate paragraph (not as "clean" as above).

I also modified a few routines that update user record to filter domain names on email notification (since we are on intranet, I don't want any "@hotmail.com" entries in there!).  If anyone is interested, I can share those too.

Cheers,
Yarko

I have the same question too

All,

You can simply create a new Theme -- we use the ASP.NET Theme/Skins system. Then you can "expose" your custom theme to Gemini via the Administration --> General section.

Current themes are stored in AppThemes.  Here are the steps:

1. Create directory under AppThemes (e.g. "OurTheme").

2. Copy files from "Default" theme directory into your new directory.

3. Rename the .css & .skin files so that they also are called OurTheme.css & OurTheme.skin.

3. Edit OurTheme.css to change colours etc.

4. Go to Gemini --> Administration --> General settings and add your theme to the existing installed theme list. 

5. Optionally, change the Default Theme setting to use your theme.

That's it.

Is it possible to put a picture (company logo) in the head? How do I have to do this? If I modify the *.skin-file there appears a ASP-Error.

This is done by changing the HeaderBar.ascx page.