To set a color for a Project, open the Project, go to the eye icon and select 'Force Colour'. Then select a color for the Project.
To remove it go back to the 'Force Colour' option and once you get the window for selecting a color hit 'Cancel' and Farmers WIFE will ask if you want to 'Remove Force Colour'. Hit 'Yes'.
To see the Project Color in the Hourline and Long Form the corresponding settings have to turned on in Toolbox > Settings > Hourline/Objects Tree > Use Project / Client Colours