[TYPO3-ttnews] Customize rte_htmlarea in tt_news

[Xatucans]

Hi, I'm tring to customize the rte_htmlarea for my news in tt_news. I write 
this code in the TSconfig of system folder where I storage my news:

RTE.config.tt_content.bodytext.showButtons = *

#CSS#
  RTE.default {
   contentCSS = fileadmin/css/disk-argital.css
   enableWordClean = 1
   useCSS = 0
   showTagFreeClasses = 1
   classesCharacter = disko-aldeak,disko-lista
   classesAnchor = disko-aldeak,disko-lista
   proc.allowedClasses = disko-aldeak,disko-lista
  }

  RTE.config.tt_content.bodytext.proc.allowedClasses <
  RTE.default.proc.allowedClasses


but it doesn't work. Could any body how can I customize it, pleas? thanks