This plugin enables HTML Markup within an APEX Tree Region which normally escapes all HTML Special characters. The idea is to use replacement characters for "<", ">" and "&" in the Tree SQL query and to configure these in the plugin. The plugin fires as a dynamic action after page load and uses some jQuery logic to activate the HTML markup by changing the replacement characters back to HTML syntax.

APEX Tree SQL query:

select case when connect_by_isleaf = 1 then 0
            when level = 1             then 1
            else                           -1
       end as status, 
       level, 
       case 
        when sal < 2500 then 
         '[b style="color: green"]'||"ENAME"||'[/b]§nbsp;[img src="https://static.oracle.com/cdn/apex/24.2.6/Fndokay1.gif" height="12"]' 
        when sal < 4500 then
         '[b style="color: black"]'||"ENAME"||'[/b]' 
        else 
         '[b style="color: red"]'||"ENAME"||'[/b]' 
       end as title,
       null as icon, 
       "EMPNO" as value, 
       null as tooltip, 
       null as link 
from "EMP"
start with "MGR" is null
connect by prior "EMPNO" = "MGR"
order siblings by "ENAME"