Even though the Develop module is disabled for video, you can still perform basic color and tonal adjustments using these methods:
Select both the edited still and the original video in the Library. Click to apply the photo's look to the video. Better Alternatives for "Full Feature" Editing
While in the Library module (press G or E ), look at the Quick Develop panel on the right side. You can adjust exposure, contrast, white balance, and vibrancy here.
Excellent for high-end color grading (free version available).