Chart Axis grid config enhancement for more than 'odd' and 'even'

[art.dev.ext]

Hi,

I'm trying to customize a scatter chart grid in order to get colored cells. But not only odd and even cells.
Something like :
Untitled.png

I've tried to add sprites to fill cells with the colors I want but facing issues when browser window gets resized (need to redraw)... I'm not satisifed with this solution.

Is it possible to extend 'grid' functionality of Axis to make cells colored depending on cell position ? Please note I've have a fixed number of cells (6x6)
CSS would be great but I'm not sure it's possible

Thank you for your help
Roy

[art.dev.ext]

Using background-image on '-main' canvas suits my needs :
bg4.jpg