The topic font color can be changed in the bottom formatting toolbar and from the Format menu.
To change the font color:
Select the topic(s) you want to color.
Do one of the following:
Click the Font
color button 
on the bottom formatting toolbar.
Click Format - Topic Font
Select the color from the color picker. The Font Color Markers group in the bottom of the picker shows the colors already in the markers list. If you select a color that's not in this group, it will be added to the Font Colors group in the Map Markers pane, where you can add a name for it (i.e. George's tasks).
Hint: You can also use font color markers as criteria for selecting topics and filtering the map.
Notes:
Once you assign a name to the new font color in the Map
Markers pane, it will appear in the map legend and it will remain
in the list of map markers regardless of whether it is used on the map.
If needed you can modify the marker name and even select a different color
to be used for this marker.
If you do not assign it a name, the marker will disappear from the list
if it is no longer used on the map.
Shortcut: You can add a marker to the selected topic(s) by clicking on it in the Map Markers Pane.
