What do the colors mean in htop?

htop screenshot

For the CPU cores, I think that blue means nice, green normal CPU use and red I/O. But I'm not sure and I haven't found a definite answer.

Then there are the colors for memory. What do green, blue and yellow mean there?

kqw

Posted 2014-01-08T03:37:55.983

Reputation: 1 781

I lack the reputation credits to flag this as duplicate, but see the answer at http://serverfault.com/questions/180711/what-exactly-do-the-colors-in-htop-status-bars-mean, which is a copy of your question and has been answered.

– Caleb Xu – 2014-01-08T04:04:38.840

1@CalebXu You cannot flag it as a duplicate of a question on another site, but you can post an actual answer here, linking to it. – slhck – 2014-01-08T08:08:03.957

Answers

Press h inside htop for quick help.

CPU

Blue      : Low-priority threads
Green     : Normal priority threads
Red       : Kernel threads
Turquoise : Virtualization threads

Memory

Green         : Used memory
Blue          : Buffers
Yellow/Orange : Cache

karel

Posted 2014-01-08T03:37:55.983

Reputation: 11 374

5For anyone wondering what's meant with cache – Abdull – 2016-10-21T16:56:53.000

Why is the kernel CPU on the right? Wouldn't it make sense to put it on the left? – Aaron Franke – 2018-02-05T19:45:03.620

@AaronFranke, because your processes are expected to primarily use User CPU. Kernel CPU is when your process calls a kernel function which should use a lot less time in %. – Alexis Wilke – 2019-10-28T00:40:45.257

Also, in the list of processes, there are some that appear in Green. The black ones are main processes and the Green ones are threads. In my example below, I'm running a repair on a Cassandra node and as we can see most entries are threads.

Alexis Wilke

Posted 2014-01-08T03:37:55.983

Reputation: 447