What colour profile should I shoot in?
Short Answer:
Choose a log or flat profile when you plan to colour grade and want maximum flexibility, and a standard profile when you need a fast turnaround with minimal grading. Log preserves the most detail in highlights and shadows but looks washed out until graded; standard profiles look good straight away but offer less latitude. The right choice depends on your post workflow and deadline.
Overview
A colour profile determines how much image data the camera records and how much work the footage needs afterwards. It is really a decision about your post-production workflow: flexibility versus speed.
Detailed Explanation
Log vs standard profiles
Log/flat profiles: capture wide dynamic range for maximum grading latitude; require grading before they look right.
Standard profiles: apply a pleasing look in-camera; ready to use quickly but less flexible.
Consistency: whatever you choose, keep it consistent across a shoot so shots match.
Document it: note the camera and profile so the colourist starts from the correct base.
Log rewards planning and a proper grade; standard profiles suit fast-turnaround work where there is no time (or need) for heavy colour work. Matching the profile to the delivery is what matters.
Example
A brand film destined for a full grade would be shot in log to protect detail, while a same-day event recap might use a standard profile so it can be edited and published quickly without grading every shot.