In Impress, if I: 1. Edit the text in some object 2. Select some of the text. 3. Set the font color, using the toolbar menubutton. 4. Select some other part of the text (so we would see the effect of a redo) 5. Open the Edit menu ... the Redo item on the menu is grayed-out. It should be available.
I was confusing Redo'ing and Repeat'ing.