Bubble - Grid - Color each cell differently - how?

[Enien19]

Hi,
I am using a bubble chart to plot risk (impact, likelihood and velocity) items. Traditionally the background would have red cells at the top right, green cells at the bottom left and yellow cells in the middle ish.

I have tried using apexcharts-canvas and an image but the main challenge is the image should just be on the grid and using position-x and y etc get it close but the grid size changes when no data and with data (the dataset names are shown).

I've also tried using the grid row and column color which seems the most accurate but cant get it to individually color each cell.

Does anyone know how to color each cell differently in the grid ??

Many thanks

Nigel