Filament change on bridges

Hi I have a problem with the supports in the bridges. I want to use the filament change so that the support does not stick to the bridge, the problem is that using the 2 different filaments also creates the filament change in the base, which I don’t want, so I avoid time for multiple filament cabs, and another problem yes detach the stand from the base . So I ask how can I eliminate the strand change in the bases? A thousand thanks
Cattura