OK, Answering my own question, it appeard it only works where the background
colour format isn't applied. Is there a way for bot formula and cell value
conditions to be considered?

"Dean F" wrote:

I have a column of calculated results. I have applied conditional formatting
to alternate colours per line, then to change the font colour for values
between 90 and 95% and also to change colour and bold values under 90%. It is
working fine on all but the first three values in the column. I have copied
from the cells below and still get the same issued. I can't see any
difference in the format or properties of these particular cells. Any
thoughts?