I need to change the font color and the backround color of the lines header of a matrix.

 I already did it for the textbox, the column headers and the values but cannot find how to change it for the lines labels. Thanks a lot  !

You can do it through CSS injection: http://www.jotform.com/help/117-How-to-Inject-Custom-CSS-Codes

Example:

.form-matrix-row-headers{

    background-color: Yellow;

    color: green;

}

Result:

Let us know if you need more help, we will be glad to assist you.