Hi,
Not a joke post, but i did make this more for fun.
Here an overview of the most common parts of themes abnd skins that are needed to define them.
level 1: basic elements - If these are not defined you didn`t even think about making a skin
.

level 2: now some elements that are needed to enhance your theme:

level 3: some aditional things that are more or less required for artistic purposes:

Why i did make this, well to show of the things, that define the look of the skins. Don`t laugh about it.
All GUIS i do know have all of this options.On linux some theme designers do only changes at level 1.
The funny thing is that you can theoretically let a computer do the rest of skinning and it would look flatpossibly , but not bad and the skin would be unique.
b.t.w: my next bright skin is coming soon.
regards bluedxca93