"There is an option to break the CPU usage graph into two sections; kernel mode time and user mode time. Many device drivers, and core parts of the operating system run in kernel mode, whereas user applications run in user mode. This option can be turned
on by choosing Show kernel times from the View menu. When this option is turned on the CPU usage graph will show a green and a red area. The red area is the amount of time spent in kernel mode, and the green area shows the amount of time spent in user mode."
(option under <view> - 'show kernel times')