While moving around the spreadsheet I can barely see the nighlighted
outline around the active cell. Can anyone help me change its color or
intensity? thanks.
Activecell highlighting is controlled by the System preferences.
Open System Preferences, select the Appearance pane, and choose a
different Highlight Color from the dropdown.
Note that this will change your highlighting system-wide.
Note also that you'll need to close and reopen XL in order for the
changes to take effect.
For an alternative, see Chip Pearson's "Rowliner" add-in:
http://cpearson.com/excel/RowLiner.htm
or my "Highlight a row without losing background colors":
http://www.mcgimpsey.com/excel/highlightrow.html#HiLiteRetainColor