thank you Walter.
i tried your code (for test can add a dummy textbox on the form to navigate with the focus and see the color change active to inactive grid).

its some complex and can be done easily with my code with box() function (posted above) and:
-a line control adjusted on the bottom grid header.
-add grid.method when() and valid() to change colors (grid.gotfocus and grid.lostfocus dont exist).