RH 2019 Release 6 includes quite a few nice enhancements, one of which is the ability to enable/disable the "Highlight Search Results" checkbox on the Indigo skin/layout.
Sadly, this is yet to be added to the rest of the skins/layouts.
Here are the exact steps on how to enable this checkbox for Azure_Blue: Note: In the event that you've found a better way or have noticed any issues with this method, please share them.
Open RH 2019 Classic
Open your project and make sure that you have added the Azure_Blue layout to it
Save All and Exit RH
Go to the path where your RH project is, and then to !ScreenLayout! -> Azure_Blue
Create a backup of the Topic.slp file
Open the Topic.slp file with Notepad
Locate and delete the 2 rows of code highlighted in yellow
Save the file
Now Open RH 2019 Classic and try generating your output again. The "Highlight Search Results" checkbox should be visible, and it should function exactly like it does with Indigo (and also the way it did with WebHelp outputs generated on older versions of Robohelp).
I've not tested this with RH 2019 Release. Only Classic
if you set the above checkbox to visible, you may have to disable/hide the "Include all words in search" one via the layout's properties. Otherwise the 2 checkboxes will have different styles, which may not look very professional.