What exactly do the colors in htop status bars mean?
Solution 1:
Hitting F1 or h will show you the key. But for reference, the default colors are:
CPU:
- Blue = Low priority threads
- Green = Normal priority threads
- Red = Kernel threads
Memory:
- Green = Used memory
- Blue = Buffers
- Yellow/Orange = Cache
There are a couple of different color-schemes available, you can see them through hitting F2.
Solution 2:
I couldn't find this documented elsewhere. Looking into the code:
There are two modes for CPU metrics reporting: the default one, and a "detailed CPU time" which can be enabled from the Setup screen (Display Options / Detailed CPU time). All of them show the percentage of time spent in different processes:
Default mode
- Blue: low priority processes (nice > 0)
- Green: normal (user) processes
- Red: kernel time (kernel, iowait, irqs...)
- Orange: virt time (steal time + guest time)
Detailed mode
- Blue: low priority threads (nice > 0)
- Green: normal (user) processes
- Red: system processes
- Orange: IRQ time
- Magenta: Soft IRQ time
- Grey: IO Wait time
- Cyan: Steal time
- Cyan: Guest time
Memory meters are more straightforward:
- Green: Used memory pages
- Blue: Buffer pages
- Orange: Cache pages
- Grey: Free (unused)
Note: Info obtained from htop source code at https://github.com/hishamhm/htop/blob/master/CPUMeter.c .
Solution 3:
There are several different colors for each of the bars, except the Swap bar. Here are the color keys used inside of htop:
