What do the colors mean in htop?

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?

Solution:

Press h inside htop for quick help.

CPU

Blue      : Low-priority threadsGreen     : Normal priority threadsRed       : Kernel threadsTurquoise : Virtualization threads

Memory

Green         : Used memoryBlue          : BuffersYellow/Orange : Cache