Layout background color

Is there a method or css setting that would enable the setting of the background color, of the layout component, from white to another color? Preferably, is there way to set the background color by layout cell.

We are using layout, grid and tabbar in which grids are attached to several layout cells or tabbar is attached to layout and grids within the tabbar. dhx_black is used for the overall skin with a modified version for grid. Everything works fine; we simply want to set the layout background color to something other than white.

If it is helpful, I can send a cut-out of a screen shot indicating precisely what area of layout we would like to alter.

See dhtmlxlayout_dhx_blue.css file:

table.dhtmlxLayoutPolyContainer_dhx_blue td.dhtmlxLayoutSinglePoly div.dhtmlxWindowMainContent {
    border: #C2D5DC 1px solid;
    background-color: #FFFFFF;