I am creating a chart and adding trendlines via VBA - which is all working
marvellously.

Each series is assigned a colour automatically. What I'd like to achieve is
to set the related trendline to be a darker version of the line colour.
However I can't see a way of finding the colour assigned to the series (which
are set as xlAutomatic by Excel)

Is this possible? Or will I have to manage the colours of the series and
trends myself?