> Check Menu-Tools-Options-Apperance-Task Format
This takes you to a section called MLO Appearance, that contains a just tick list - all of which I have already got ticked.
> Menu-Tools-Options-Themes and Formating-Edit
Ah.... Cunningly hidden! Yes, that's the one.
FWIW, under the "Fonts & Icons" tab (but not under "Task Format"), you can change the format of Tasks by clicking the "..." next to the font name, and you have an albeit rather limited choice of just 16 colours to choose form.
Many thanks.
J