You can't change the colour of the filter arrow.
However, if you can use programming, you can colour the heading cell of
the filtered column. There's a sample he
http://www.contextures.com/excelfiles.html
Under Filters, look for 'Colour Filter Headings'
Tanguy Huysmans wrote:
When I apply a filter to an Excel spreadsheet, the arrows
at the top of each column are black. When I apply the
filter to a column, the arrow turns blue. I am having
difficulty seeing the color difference and was wondering
if there is a way to change the color for the arrows so
that when the filter is applied it turns a brighter color
(perhaps red?)...
If anyone knows how to do this, I would appreciate hearing
from you.
--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html