SW1-3 are publicly testable.
A few years ago it wasnt. Out of curiosity: where?
http://www.vgl.ucdavis.edu/services/horse/splashedwhite.php
http://www.horsetesting.com/splash.htm
It’s fairly new 
It’s been fascinating following the tested horses, and especially seeing who looks so very splash but isn’t any of these 3 
It’s also looking like between the SW and W testing, one of the W genes mimics splash pretty well, though atm I don’t remember which one - one of the more recently known W genes though
my Arabs look very much splash and some of my Warmbloods do too but they were W19 (Arabs) or W20 (Warmbloods). Whereas it seems that Splash do not need to look like splashed white obviously but can be it anyway. That is why these tests are so very interesting for scientists and horse owner that either like or dislike white “markings”.
