This is an example of Pivot Grid with custom style of the grid cells depending on their current value. You can change the
rendering of any cell, row or column and insert your own HTML content by implementing the itemsRenderer and cellsRenderer functions.
In this case, the custom code simply chooses among five predefined colors and sets the backgroundColor property of the
cell content. This color customization is applied only to the cells with 'Sum' aggregation function. You can change
the code of the itemsRender and cellsRenderer functions and implement your own customization logic using standard HTML and CSS.