Does anyone know if the colour of a bubble within a chart can be
conditionally formatted through reference to a cell within the spreadsheet ?

I want the colour of each bubble within the chart to based on the result of
a calculation within the spreadsheet. Currently the cells containing the
calculation are conditionally formatted to give a red, amber, green result
and I want to link the colour of the conditionally formatted cells to the
colour of the associate bubble.
(At the moment I update the bubbles manually)