Apply Changes to SharePoint Theme to all sites and subsites

This post can be used to resolve two problems/issues of SharePoint 2007/2010 and WSS 3.0.

• When you define the site theme, is created the _themes folder on the site (you can view this on SPD), but when you change the css, of the theme, the changes are not propagated to this folder.
  
• When you create a site, it does not inherit the theme used on the parent site, so for each site that you create you need to define the theme for it.
  

To resolve the first issue you need to:

1. Make the changes that you want to the css on your theme (C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\THEMES\XYZ)
   
2. Recycle the application pool or iisreset
   
3. Go to your site then Site Actions > Site Settings > Site Theme, change the theme to another one
   
4. Go again to Site Actions > Site Settings > Site Theme, and choose your theme.
   
5. Now the css is updated.
   

To resolve the second issue you need to:

1. Change the top site to the theme of your choice going to Site Actions > Site Settings > Site Theme.
   
2. Navigate to the top site to see the newly applied theme.
   
3. View the HTML source of the SharePoint page using the theme you want.
   
4. Look for a link tag containing the .css file for the applied theme.  It will look something like this:
   <link rel="stylesheet" type="text/css" id="onetidThemeCSS" href="/SITE/_themes/Belltown/Bell1011-65001.css?rev=12%2E0%2E0%2E4518" mce_href="/SITE/_themes/Belltown/Bell1011-65001.css?rev=12%2E0%2E0%2E4518"/>
   
5. Copy the href value to your clipboard or to a text file if you like.  It should look something like:
   /SITE/_themes/Belltown/Bell1011-65001.css
   
6. On your top level site, go to the Site Actions > Site Settings > Master Page screen.
   
7. Scroll to the bottom where the Alternate CSS URL section is.  Select the "Specify a CSS file…" option.
   
8. Paste the path copied from the href above into the text box.
   
9. Check the Reset all sub-sites to inherit this alternate CSS URL option.
   
10. Click OK.
    
11. Navigate to your sub-sites and verify the theme has been applied.
    

With this to configurations, you can update your theme, and propagate your changes to all your sites and subsites.