How to Change My High lighting color in a Desktop Theme

I decided it was time for me to change my desktop theme but the age old problem reared it's ugly head again ..... a black on black background color .... see photo below .....

This keeps me from using a whole bunch of other themes as only my Cinnamox-Willow-Grove has a very vivid highlighting color .... a florescent type of light green color which really pops .... see 2nd photo below ....

I am trying to use a combo of themes with my Cinnamon DE and are as follows ....

Window borders ---- silverdeck ----- Aravisian

Icons ---- Winter Mist ---- Storm

Controls ---- vallis ---- Aravisian

Mouse Pointer ---- Oxygen 34 Gray Ghost ---- Pling

Desktop ---- cinnamon ---- Pling

This is what I would like to have .... something like this .....

It's a shame Compiz is no longer present in the OS.

18 minutes in.

Have you tried a custom gtk.css placed in ~/.config/gtk-3.0 directory?
Use:

 .view text:hover, iconview text:hover, textview text:hover, iconview text:hover:focus, textview text:hover:focus, flowbox flowboxchild:hover, .view text:selected, iconview text:selected, textview text:selected, iconview text:selected:focus, textview text:selected:focus, .view text selection:focus, iconview text selection:focus, .view text selection, iconview text selection, textview text selection:focus, textview text selection, flowbox flowboxchild:selected, entry selection, entry selection:focus {
     background-color: rgba(25, 250, 55, 0.3);
}

For some reason I can't find the ~/.config/gtk-3.0 ..... see Photo #1 & 2 ..... do I have to make that folder ??????

I do apparently have high-lite in Zorin itself ..... see Photo #3

I also changed high-lite in Vivaldi ....

But this didn't change anything on the Zorin forum only in Vivaldi .....

Photo 1 and 2 show that you have that folder and that it has a gtk.css file in it already.

DUH ..... for some strange reason I was looking at that folder s being gk instead of gtk ..... optometrist here I come ..... :tired_face:

OK now let me try it and see what happens .... I just copy all the info into the folder or type it ?????????

Must of done something wrong when I copied and pasted ...... I did hit the save button at the top of the screen and also restarted the OS .....

OK I deleted the mess I made and re-entered the info ..... but still nothing ....