stringing (PLA Filament) seems really frustrating; i have tried the various techniques on the how-to videos and still can’t seem to get over this hump;
how about this ?:
use Cura’s ‘model-within-a-model’ capability to regionalize rectangular sections that are stringing candidates and dramatically slow the print speed in those regions;
i think one of the sub-timings in cura has to do with ‘fine detail’ so cura may be doing some of that slowing already but i cant really say;
i reached out to the printer manufacturer and am their maximum retraction distance (apparently based on nozzle length) and have bumped the retraction speed up 50 % from the cura printer default for that printer;
a fringe idea: seems that different colors can require different printing temps due to how much additives that filamant contains; does this also suggest that different colors might string more or less ?
thoughts ?
There are so many variables that can affect stringing dealing with it is more witch craft then science.
What is your retraction distance? Bowden or direct drive? I run 7.5mm retraction at 45mm/s on my bowden ender 3s. Some would say that is way too much, but it works for me with minimal stringing. 
I guess what I am saying is, try upping your retraction distance anyway. Worst that can happen is a clog. You don’t know till you try. Another thing to check if you are running a bowden setup is the shark bite fittings that hold the bowden tube. Make sure there is no slop that allows you to pull the bowden tube in and out, effectively eating up retraction distance.
Might be worth it to run temperature and retraction towers with each filament. See if they point to anything in particular.