Thank you !
I found it.
I change values (font color, font size and
description height)
But these changes are not apply in front of my web site. I don't understand.
My description height in back office is for example 100, in my database the description height = 100 -> OK
But on my web site the description height is not 100.
I use joomla 1.5.6 with phoca 1.6.2 beta.
I use too joomla 1.5.7 with phoca 1.8.8.