I have a load of GoPro video files added within the timeline of Rush. If I select a single file then 'colour' I can change the colour ok. If I select ALL or multiple video clips then Colour the option to apply a colour is greyed out.
This works with transitions, i.e I can select all clips and then a transition which is added to all clips.
Image below is a single image, you can see the colour options are available.
The below image has 2 selected, but the colour options are greyed out and cannot be selected