There is not made a distinction for the 2.2.x themes.
In principle everything from old works.
The newer contains specific tags as xoAppUrl and xoImgUrl, which are not supported by 2.2.x, but these can be edited for backwards compatibillity.
Replace eg
<{xoAppUrl /images/logo.png}>
by
<{$xoops_url}>/images/logo.png
and
<{xoImgUrl img/xoops_logo.png}>
by
<{$xoops_imageurl}>img/xoops_logo.png
Watch out for
<{xoAppUrl /user.php op=login}>
=>
<{$xoops_url}>/user.php?op=login
Other replacements are:
$xoBlocks.canvas_left => $xoBlocks.canvas_left
$xoBlocks.canvas_right => $xoBlocks.canvas_right
$xoBlocks.page_topcenter => $xoBlocks.page_topcenter
$xoBlocks.page_topleft => $xoBlocks.page_topleft
$xoBlocks.page_topright => $xoBlocks.page_topright
$xoBlocks.page_bottomcenter => $xoBlocks.page_bottomcenter
$xoBlocks.page_bottomleft => $xoBlocks.page_bottomleft
$xoBlocks.page_bottomright => $xoBlocks.page_bottomright
In some themes:
<{assign var=theme_name value=$xoops_rootpath|cat:'/themes/'|cat:$xoops_theme}>
<{assign var=theme_tpl value=$theme_name|cat:'/tpl'}>
=>
<{assign var=theme_name value=$xoTheme->folderName}>
<{assign var=theme_tpl value=$xoTheme->folderName|cat:'/tpl'}>
Comment out messagebox indicator:
<{xoInboxCount assign=pmcount}>
<a href="<{xoAppUrl viewpmsg.php}>">
<{if $pmcount}>
" alt="(<{$pmcount}>) <{$smarty.const.THEME_NOTREAD}>"/>
<{else}>
<img src="<{xoImgUrl icons/users/inbox.png}>" alt="<{$smarty.const.THEME_MESSAGE}>"/>
<{/if}>
a>
=>
<{* xoInboxCount assign=pmcount *}>
<a href="<{$xoops_url}>/viewpmsg.php">
<{* if $pmcount}>
/themes/ds_red/icons/users/inbox-full.png" alt="(<{$pmcount}>) <{$smarty.const.THEME_NOTREAD}>"/>
<{else *}>
<img src="<{$xoops_url}>/themes/ds_red/icons/users/inbox.png" alt="<{$smarty.const.THEME_MESSAGE}>"/>
<{* /if *}>
a>