google translate
I managed to solve it with the following CSS: .x-column-header { border-right: 1px 1px 1px 1px; border-left: 1px 1px 1px 1px; border-top: 1px 1px 1px 1px; border-bottom: 1px 1px 1px 1px; color: #000; /* -- GRID HEADER FONT COLOR -- */ background-color: #F0F8FF; font: 400 13px 'Segoe UI', 'Open Sans', 'Helvetica Neue', helvetica, arial, verdana, sans-serif !important; }