Color Coding in MS Project

I am currently using MS project to manage employee on different jobsites. I created a resource list for all the employees and created Gantt Chart of all project. I am having two issues and looking if anyone can help men out:

1) The task usage view currently has employee hours broken down by day in the timescale. Employee vacation are displayed as 0. Im trying to find a way to color code those vacation days so as to make timescale visually appealing.

2) I am curently manully updating employee vacation and time off using the Task Usage view and inputting 0 for the vacation days. Is there a better way of doing this? I tried using resource calendar but there is way too many employees