A file called style.vm for example
<HTML>
<HEAD>
#IF(cliente == 1)
<link rel="stylesheet" type="text/css" href="cliente1.css">
#ELSE IF (cliente == 2)
<link rel="stylesheet" type="text/css" href="cliente2.css">
#ELSE IF (cliente == 3)
<link rel="stylesheet" type="text/css" href="cliente3.css">
#ELSE IF (cliente == 4)
<link rel="stylesheet" type="text/css" href="cliente4.css">
.
.
.
#END
<HEAD>
</HTML>
and in the other .VMs and .JSPs you get the css that was defined in that file, because you did not want to copy all those IFs to each project file. I have the option of using JQuery if necessary, as all pages of this project import JQuery.