Differentiate memory options with slightly altered icons

[stuartlangridge]

Describe the new feature you'd like Currently I have Vitals showing the Available Memory and the Swap Used in my top panel. However, it's difficult to remember which way round that Vitals displays these in:

Is this 2GB free and 3GB of swap used, or the other way around? Maybe I could learn the order, but I just can't remember it, and indicating what a number represents is what icons are for :-)

It would be very useful if the different memory statistics used (slightly) different icons, thus making this more obvious.

This is a feature request rather than a pull request because I'm not sure what the new icons should be (and because I'm not good at art). My original thought was to adapt the memory icon (a symbolic representation of a RAM chip) to have a letter in it centrally: "T" for Total ("Physical"), "F" for Free ("Available"), "U" for Used ("Allocated") and S for Swap Used. However, this is English-specific, so it's not ideal (and the letters don't match the existing labels, but the existing labels letters would be P, A, A, S, which doesn't help).

I'm not good enough at art to think of some way to represent each of total , used, free, and swap in four different symbolic icons. But hopefully someone else is!

[bilwit]

selectable color background would be the way instead of icons