I agree,
would love to be able to edit to my own colour scheme
, or bring back the old colour definitions. Not worried about ‘keeping it streamlined’ with other mac software, this is a database with a purpose, the purpose is to enable users to use their database quickly - it’s always worked how it should, colour options would make it easier for the user to see at a glance where they are in their listings, bright colours, a big thumbs up from an old school user! 
I agree with others here who didn’t like some of the changes made in GS7. After upgrading from GS6 to GS7, it was disappointing to see the things I had lost as a result, like color in many aspects of the interface (menu icons, auction template states) and the ability to customize the toolbar.
I realize Apple has removed much of the color from macOS, but it would be great if GS7 gave us the option to have color back if we want it. I find it much easier to distinguish interface elements when they are a different color.
The option to change colors to what i want…YES PLEASE!!
Looking at hundreds of “eBay” Icons is almost ridiculous, like brainwashing 
I agree >>> “Color Highlighting of the Entire Title to denote “listing state” was much more easy to distinguish at a glance as many people have mentioned.”
I spend twice as long trying to distinguish which is listed, sold, etc. I even go to eBay just to make sure…Not streamlined for me.
Also what happened to the little numbers next to the titles while Folders are closed, noting there is an auction running in it? Did I just dream that? I thought it use to show them.
We still have the numbers next to our folders, whether they are open or closed. One thought though: The parent folder’s count does not include the count of items listed within subfolders. Might want to change that if not too much trouble.
I would assume that they are expanding GS7 to handle listings to other auction or for sale sites, therefore I completely understand why each listing has the eBay icon. A bit of brain-washy now for certain, but for those who take advantage of the new feature whenever it is released, I have no doubt that it will be welcome.
Has the feature to customize the color of icons been added yet?
Sorry, no, it’s more a feature for a future version.
Regards, Kristian
And will the option to create ones own class be available as well?
E.g. a listing that I want to keep but one that has been sold outside of Ebay after contacting the purchaser directly. (Not that I would ever contemplate the idea - LOL).
I would also appreciate to have different, bolder colors for the icons to make them better recognizable. I would not need customizable ones, the option to choose three or four different versions of the existing sets would be enough for me.