grid headers in our own background ?

how to change the grid headers in our own background colors and text as aligned to center and bold?

Example -

#myGrid .aw-grid-header {
    background: red!important;
    font-weight: bold;
    text-align: center;
}

#myGrid .aw-grid-header .aw-item-box {
    background: none;
    border: none;
}