I believe this may be one of the incompatibilities between 2007 and 2008.
Conditional color formatting and filter or sort by color don't appear in
2008 or are a subset.
What I suggest as a workaround is to filter by color, then in an added
field, place a code you define to represent the color. Then when you get the
data to 2008, filter on this new field, and re-establish colors that 2008
Yes, I know it's ugly.