A variety of colour correction tools and effects are available, each of which can be applied independently to individual segments on the timeline.
Since each segment can have a different set of effects, the effects tree to the left of the composition editor will always show all the colour correction layers and effects that can be applied to the active segment on the timeline:
As the active segment changes, the effects tree will change to show only the effects corresponding to that segment.
A selected segment is orange, but this does not override the active segment with regards to the effects tree.
By default, only the basic colour correction layers appear in the effects tree. These are the Base layer and the Master layer. Additional colour correction layers and effects can be added using the effects toolbar, which runs along the bottom of the composition editor.
Segments that have had grading/effects applied are differentiated on the timeline from those that haven't by having a lighter segment colour; i.e. segments with effects are whiter than the grey segments without effects.
In addition, if you have thumbnails enabled, the thumbnails in each timeline segment will show the first and last frames of the segment with the effects that have been applied.
The following effects operations will be covered in the next sections: