Themes and color coded templates

Just started with excel 2016 and have found a couple templates I would like to use but need to adjust them to meet my needs. For the life of me I can not wrap my head around how the themes and colors works. Some color codes come back with the wrong colors. Some don't even have color. I have changed some of the accent colors and seen no change in the template at all.

I have been working with the "Employee Attendance tracker" and the "Employee Absence Schedule" templates and struggling with both of these.

Please post a copy of the file you are looking at.

the attached file is the template after i have made a few changes. the changes that were made were additions to the "key Statistics" section with the addition of a few things we track.
The color codes don't always match with the color key and the "OT/DT" color codes don't even show up on the chart. If I put anything an a weekend it does nothing with color or accumulate
in the statistics.

can anyone explain how colors are applied in the file above