Sure you can, just select your time range and then select your color from
Categorize. You don't have to enter anything in the subject.

"wvjoe" wrote:

Is there a way to color code blocks of time on the calendar without actually
entering appointments? For example, I would like to color code 7am to 5pm in
yellow, 5pm to 8pm in green, and 9-10pm in red. I understand that I can
apply color labels to appointments, but I would like to color code the
'block' without having to enter appointments.