(TL;DR just look at the images if you're strapped on time, but make sure to follow step 3!)
You can do this through the registry! Not only can you change the hot tracking color, but you can also change the text highlight color! For example, here are a green hot tracking color and a green text highlight color:
This generally works best on a similarly colored but darker wallpaper. This answer seems lengthy but in reality, it should only take 5 minutes. Anyway, here are the steps to accomplish this:
Open the registry editor with admin privileges. The reason you want to open it with admin privileges is because otherwise, the changes you make probably won't save next time you log in. (Windows Update messes things up sometimes as well...)
For example, you can press the ⊞ Windows key, type regedit, and once Windows search finds the program for you, you can press Shift+Alt+Enter to open it with admin privileges. It's going to ask you if you really want to open it in elevated mode, so you should say "yes".
Once you've got Regedit open, navigate to the relevant section: Computer > HKEY_CURRENT_USER > Control Panel > Colors.
Note: you will notice that these color settings apply only to the current user, not all users. If you want to customize all user accounts, you will have to repeat this entire process for every unique account.
Before you do anything else, make sure to make a backup of the registry! In case you mess something up, a backup will ensure you can rollback to the previous settings. It's very easy to back it up (just 3 clicks), here are the instructions on Microsoft's website.
The keys you're going to want to change are called "HotTrackingColor" and "Hilight", to change the hot tracking color and the text background highlight color respectively. Double click on a key to change its value. The key "HilightText" changes the color of the letters instead of the background.
The color values are in RGB (Red Green Blue) format, so you can go to https://www.htmlcolor-picker.com to find a color you like.
In fact, you can play around with any of the color keys, but that is not the topic of this answer. Once you are satisfied with your changes, export your registry so you can use it again later without having to do it all over again.
Finally, restart your computer to hopefully see the changes take effect. If you still don't see the changes take effect after a restart, that means you need to follow a few more steps to solve this issue. If it works for you once but it doesn't work the next time you turn on your computer, it's probably because you didn't explicitly choose "Hibernate" instead of "Shut down" because "Shut down" doesn't save trivial settings like the color ones (this is not bashing those who dislike hibernate, but offering a possible explanation).
Bonus steps in case it still doesn't work:
We are going to use the task scheduler utility to run your exported registry file every time you log in. This should guarantee that your custom changes take effect. To get started, open the .
Press "Create Task". Under the General tab, choose a name, description, set it to "Run whether user is logged on or not", and configure the settings to work on the appropriate operating system. Mine is Windows 10.
Open the Triggers tab and click on "New". Under "Begin the task", choose "At log on" from the drop down menu, and then choose "Specific user". After you click "OK", repeat the process again but instead of "At log on", choose "On unlock" (this may say "On workstation unlock").
Next, under the Actions tab, click on "New" and then browse for the exported registry file you created in step five.
Under the Conditions tab, choose whichever settings you prefer, although I would recommend un-checking everything. However, the Settings tab really is up to you. Click "OK" when you're done.
This time for sure! Restart your computer and hopefully the changes will take effect!