like putting style to a cell depending on the value that

Could you explain what you are trying to do? It wasn't very clear.

for example if particular cell has 100 value turns red
another cell has a value of <20 This green
and if in> 60 yellow
the same for the row and column

Use the grid event handler function with a custom column, and it should work fine.

    /**
     * 
     * @param GridRow $row The grid row object
     * @param array $args No Data
     */
    function OnRowPreRender($row,$args)
    {
        // check for value here
        if(  $row->DataItem['YourFieldNameWithTheValue'] >= 100 )
        {
            $row->DataItem['YourFieldNameWithTheValue']  = '<div style="color:red;">' . $row->DataItem['YourFieldNameWithTheValue']  . '</div>' ;
        }
    }

thank you very much works well with values
but by putting the bottom of the single cell shades on values and not on the cell
how could I do to make the bottom of the cell is changed in all of it?
I have a code in Javascript, it does, but nose and handle it with the code you sent me in php
var _mastertable = grid_solicitudes_generadas.getMasterTable();
var _rows = _mastertable.getRows();
var _first_row = _rows[2];
var _cells = _first_row.getCells();
_cells[2].getElement().style.backgroundColor="red";

It sounds like to need to create a css block and assign the items in it as important.
In the css you need to define what your cell will look like.
Or
In your custom column, just build out the table you would like to display data with and format it via the css.
Assign the css via php or javascript then.
It's really a choice.

ok could have something like
function OnRowPreRender($row,$args)
{
// check for value here
if( $row->DataItem['YourFieldNameWithTheValue'] >= 100 )
{
$row->CellStyle['YourFieldNameWithTheValue'] = 'red' ;
}
}